whisper : add grammar-based sampling (#1229)

* whisper : add grammar-based sampling

* build : fix after master merge

* command : fix exception when recognizing the command

* whisper : fine-tuning grammar functionality

* command : grammar-related improvements

- option to read grammar from file
- add sample grammars for colors and chess moves
- fine-tune the performance further

* grammars : add assistant + update comments

* command : enable beam-search, add "no_timestamps", add "context", add p

* whisper : remove comment

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
This commit is contained in:
Evan Jones 2023-11-13 03:51:34 -05:00 committed by GitHub
parent c23598e4ca
commit 3e5c7feeff
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
10 changed files with 1287 additions and 67 deletions

View File

@ -362,8 +362,8 @@ quantize: examples/quantize/quantize.cpp $(WHISPER_OBJ) $(SRC_COMMON)
stream: examples/stream/stream.cpp $(SRC_COMMON) $(SRC_COMMON_SDL) $(WHISPER_OBJ)
$(CXX) $(CXXFLAGS) examples/stream/stream.cpp $(SRC_COMMON) $(SRC_COMMON_SDL) $(WHISPER_OBJ) -o stream $(CC_SDL) $(LDFLAGS)
command: examples/command/command.cpp $(SRC_COMMON) $(SRC_COMMON_SDL) $(WHISPER_OBJ)
$(CXX) $(CXXFLAGS) examples/command/command.cpp $(SRC_COMMON) $(SRC_COMMON_SDL) $(WHISPER_OBJ) -o command $(CC_SDL) $(LDFLAGS)
command: examples/command/command.cpp examples/grammar-parser.cpp $(SRC_COMMON) $(SRC_COMMON_SDL) $(WHISPER_OBJ)
$(CXX) $(CXXFLAGS) examples/command/command.cpp examples/grammar-parser.cpp $(SRC_COMMON) $(SRC_COMMON_SDL) $(WHISPER_OBJ) -o command $(CC_SDL) $(LDFLAGS)
lsp: examples/lsp/lsp.cpp $(SRC_COMMON) $(SRC_COMMON_SDL) $(WHISPER_OBJ)
$(CXX) $(CXXFLAGS) examples/lsp/lsp.cpp $(SRC_COMMON) $(SRC_COMMON_SDL) $(WHISPER_OBJ) -o lsp $(CC_SDL) $(LDFLAGS)

View File

@ -23,6 +23,7 @@ add_library(${TARGET} STATIC
common.cpp
common-ggml.h
common-ggml.cpp
grammar-parser.cpp
)
include(DefaultTargetOptions)

View File

@ -9,6 +9,7 @@
#include "common-sdl.h"
#include "common.h"
#include "whisper.h"
#include "grammar-parser.h"
#include <sstream>
#include <cassert>
@ -21,6 +22,11 @@
#include <vector>
#include <map>
bool file_exists(const std::string & fname) {
std::ifstream f(fname.c_str());
return f.good();
}
// command-line parameters
struct whisper_params {
int32_t n_threads = std::min(4, (int32_t) std::thread::hardware_concurrency());
@ -30,8 +36,12 @@ struct whisper_params {
int32_t max_tokens = 32;
int32_t audio_ctx = 0;
float vad_thold = 0.6f;
float freq_thold = 100.0f;
float vad_thold = 0.6f;
float freq_thold = 100.0f;
float grammar_penalty = 100.0f;
grammar_parser::parse_state grammar_parsed;
bool speed_up = false;
bool translate = false;
@ -45,6 +55,8 @@ struct whisper_params {
std::string fname_out;
std::string commands;
std::string prompt;
std::string context;
std::string grammar;
};
void whisper_print_usage(int argc, char ** argv, const whisper_params & params);
@ -75,6 +87,9 @@ bool whisper_params_parse(int argc, char ** argv, whisper_params & params) {
else if (arg == "-f" || arg == "--file") { params.fname_out = argv[++i]; }
else if (arg == "-cmd" || arg == "--commands") { params.commands = argv[++i]; }
else if (arg == "-p" || arg == "--prompt") { params.prompt = argv[++i]; }
else if (arg == "-ctx" || arg == "--context") { params.context = argv[++i]; }
else if ( arg == "--grammar") { params.grammar = argv[++i]; }
else if ( arg == "--grammar-penalty") { params.grammar_penalty = std::stof(argv[++i]); }
else {
fprintf(stderr, "error: unknown argument: %s\n", arg.c_str());
whisper_print_usage(argc, argv, params);
@ -109,16 +124,30 @@ void whisper_print_usage(int /*argc*/, char ** argv, const whisper_params & para
fprintf(stderr, " -f FNAME, --file FNAME [%-7s] text output file name\n", params.fname_out.c_str());
fprintf(stderr, " -cmd FNAME, --commands FNAME [%-7s] text file with allowed commands\n", params.commands.c_str());
fprintf(stderr, " -p, --prompt [%-7s] the required activation prompt\n", params.prompt.c_str());
fprintf(stderr, " -ctx, --context [%-7s] sample text to help the transcription\n", params.context.c_str());
fprintf(stderr, " --grammar GRAMMAR [%-7s] GBNF grammar to guide decoding\n", params.grammar.c_str());
fprintf(stderr, " --grammar-penalty N [%-7.1f] scales down logits of nongrammar tokens\n", params.grammar_penalty);
fprintf(stderr, "\n");
}
std::string transcribe(whisper_context * ctx, const whisper_params & params, const std::vector<float> & pcmf32, float & prob, int64_t & t_ms) {
std::string transcribe(
whisper_context * ctx,
const whisper_params & params,
const std::vector<float> & pcmf32,
const std::string & grammar_rule,
float & logprob_min,
float & logprob_sum,
int & n_tokens,
int64_t & t_ms) {
const auto t_start = std::chrono::high_resolution_clock::now();
prob = 0.0f;
logprob_min = 0.0f;
logprob_sum = 0.0f;
n_tokens = 0;
t_ms = 0;
whisper_full_params wparams = whisper_full_default_params(WHISPER_SAMPLING_GREEDY);
//whisper_full_params wparams = whisper_full_default_params(WHISPER_SAMPLING_GREEDY);
whisper_full_params wparams = whisper_full_default_params(WHISPER_SAMPLING_BEAM_SEARCH);
wparams.print_progress = false;
wparams.print_special = params.print_special;
@ -126,19 +155,41 @@ std::string transcribe(whisper_context * ctx, const whisper_params & params, con
wparams.print_timestamps = !params.no_timestamps;
wparams.translate = params.translate;
wparams.no_context = true;
wparams.no_timestamps = params.no_timestamps;
wparams.single_segment = true;
wparams.max_tokens = params.max_tokens;
wparams.language = params.language.c_str();
wparams.n_threads = params.n_threads;
wparams.audio_ctx = params.audio_ctx;
wparams.speed_up = params.speed_up;
wparams.audio_ctx = params.audio_ctx;
wparams.speed_up = params.speed_up;
wparams.temperature = 0.4f;
wparams.temperature_inc = 1.0f;
wparams.greedy.best_of = 5;
wparams.beam_search.beam_size = 5;
wparams.initial_prompt = params.context.data();
const auto & grammar_parsed = params.grammar_parsed;
auto grammar_rules = grammar_parsed.c_rules();
if (!params.grammar_parsed.rules.empty() && !grammar_rule.empty()) {
if (grammar_parsed.symbol_ids.find(grammar_rule) == grammar_parsed.symbol_ids.end()) {
fprintf(stderr, "%s: warning: grammar rule '%s' not found - skipping grammar sampling\n", __func__, grammar_rule.c_str());
} else {
wparams.grammar_rules = grammar_rules.data();
wparams.n_grammar_rules = grammar_rules.size();
wparams.i_start_rule = grammar_parsed.symbol_ids.at(grammar_rule);
wparams.grammar_penalty = params.grammar_penalty;
}
}
if (whisper_full(ctx, wparams, pcmf32.data(), pcmf32.size()) != 0) {
return "";
}
int prob_n = 0;
std::string result;
const int n_segments = whisper_full_n_segments(ctx);
@ -147,19 +198,17 @@ std::string transcribe(whisper_context * ctx, const whisper_params & params, con
result += text;
const int n_tokens = whisper_full_n_tokens(ctx, i);
for (int j = 0; j < n_tokens; ++j) {
const int n = whisper_full_n_tokens(ctx, i);
for (int j = 0; j < n; ++j) {
const auto token = whisper_full_get_token_data(ctx, i, j);
prob += token.p;
++prob_n;
if(token.plog > 0.0f) exit(0);
logprob_min = std::min(logprob_min, token.plog);
logprob_sum += token.plog;
++n_tokens;
}
}
if (prob_n > 0) {
prob /= prob_n;
}
const auto t_end = std::chrono::high_resolution_clock::now();
t_ms = std::chrono::duration_cast<std::chrono::milliseconds>(t_end - t_start).count();
@ -250,7 +299,7 @@ int process_command_list(struct whisper_context * ctx, audio_async &audio, const
fprintf(stderr, " ]\n");
}
std::string k_prompt = "select one from the available words: ";
std::string k_prompt = "select one from the available words: ";
for (int i = 0; i < (int) allowed_commands.size(); ++i) {
if (i > 0) {
k_prompt += ", ";
@ -418,7 +467,9 @@ int always_prompt_transcription(struct whisper_context * ctx, audio_async & audi
bool is_running = true;
bool ask_prompt = true;
float prob = 0.0f;
float logprob_min = 0.0f;
float logprob_sum = 0.0f;
int n_tokens = 0;
std::vector<float> pcmf32_cur;
@ -456,7 +507,7 @@ int always_prompt_transcription(struct whisper_context * ctx, audio_async & audi
// detect the commands
audio.get(params.command_ms, pcmf32_cur);
const auto txt = ::trim(::transcribe(ctx, params, pcmf32_cur, prob, t_ms));
const auto txt = ::trim(::transcribe(ctx, params, pcmf32_cur, "", logprob_min, logprob_sum, n_tokens, t_ms));
const auto words = get_words(txt);
@ -492,18 +543,27 @@ int always_prompt_transcription(struct whisper_context * ctx, audio_async & audi
// general-purpose mode
// freely transcribe the voice into text
int process_general_transcription(struct whisper_context * ctx, audio_async &audio, const whisper_params &params) {
int process_general_transcription(struct whisper_context * ctx, audio_async & audio, const whisper_params & params) {
bool is_running = true;
bool have_prompt = false;
bool ask_prompt = true;
float prob0 = 0.0f;
float prob = 0.0f;
float logprob_min0 = 0.0f;
float logprob_min = 0.0f;
float logprob_sum0 = 0.0f;
float logprob_sum = 0.0f;
int n_tokens0 = 0;
int n_tokens = 0;
std::vector<float> pcmf32_cur;
std::vector<float> pcmf32_prompt;
const std::string k_prompt = "Ok Whisper, start listening for commands.";
std::string k_prompt = "Ok Whisper, start listening for commands.";
if (!params.prompt.empty()) {
k_prompt = params.prompt;
}
fprintf(stderr, "\n");
fprintf(stderr, "%s: general-purpose mode\n", __func__);
@ -536,9 +596,11 @@ int process_general_transcription(struct whisper_context * ctx, audio_async &aud
// wait for activation phrase
audio.get(params.prompt_ms, pcmf32_cur);
const auto txt = ::trim(::transcribe(ctx, params, pcmf32_cur, prob0, t_ms));
const auto txt = ::trim(::transcribe(ctx, params, pcmf32_cur, "prompt", logprob_min0, logprob_sum0, n_tokens0, t_ms));
fprintf(stdout, "%s: Heard '%s%s%s', (t = %d ms)\n", __func__, "\033[1m", txt.c_str(), "\033[0m", (int) t_ms);
const float p = 100.0f * std::exp(logprob_min0);
fprintf(stdout, "%s: Heard '%s%s%s', (t = %d ms, p = %.2f%%)\n", __func__, "\033[1m", txt.c_str(), "\033[0m", (int) t_ms, p);
const float sim = similarity(txt, k_prompt);
@ -559,19 +621,30 @@ int process_general_transcription(struct whisper_context * ctx, audio_async &aud
// we have heard the activation phrase, now detect the commands
audio.get(params.command_ms, pcmf32_cur);
//printf("len prompt: %.4f\n", pcmf32_prompt.size() / (float) WHISPER_SAMPLE_RATE);
//printf("len command: %.4f\n", pcmf32_cur.size() / (float) WHISPER_SAMPLE_RATE);
// prepend 3 second of silence
pcmf32_cur.insert(pcmf32_cur.begin(), 3.0f*WHISPER_SAMPLE_RATE, 0.0f);
// prepend the prompt audio
pcmf32_cur.insert(pcmf32_cur.begin(), pcmf32_prompt.begin(), pcmf32_prompt.end());
const auto txt = ::trim(::transcribe(ctx, params, pcmf32_cur, prob, t_ms));
const auto txt = ::trim(::transcribe(ctx, params, pcmf32_cur, "root", logprob_min, logprob_sum, n_tokens, t_ms));
prob = 100.0f*(prob - prob0);
//const float p = 100.0f * std::exp((logprob - logprob0) / (n_tokens - n_tokens0));
const float p = 100.0f * std::exp(logprob_min);
//fprintf(stdout, "%s: heard '%s'\n", __func__, txt.c_str());
// find the prompt in the text
float best_sim = 0.0f;
size_t best_len = 0;
for (int n = 0.8*k_prompt.size(); n <= 1.2*k_prompt.size(); ++n) {
for (size_t n = 0.8*k_prompt.size(); n <= 1.2*k_prompt.size(); ++n) {
if (n >= txt.size()) {
break;
}
const auto prompt = txt.substr(0, n);
const float sim = similarity(prompt, k_prompt);
@ -584,9 +657,16 @@ int process_general_transcription(struct whisper_context * ctx, audio_async &aud
}
}
const std::string command = ::trim(txt.substr(best_len));
fprintf(stdout, "%s: DEBUG: txt = '%s', prob = %.2f%%\n", __func__, txt.c_str(), p);
if (best_len == 0) {
fprintf(stdout, "%s: WARNING: command not recognized, try again\n", __func__);
} else {
// cut the prompt from the decoded text
const std::string command = ::trim(txt.substr(best_len));
fprintf(stdout, "%s: Command '%s%s%s', (t = %d ms)\n", __func__, "\033[1m", command.c_str(), "\033[0m", (int) t_ms);
}
fprintf(stdout, "%s: Command '%s%s%s', (t = %d ms)\n", __func__, "\033[1m", command.c_str(), "\033[0m", (int) t_ms);
fprintf(stdout, "\n");
}
@ -654,12 +734,36 @@ int main(int argc, char ** argv) {
int ret_val = 0;
if (!params.commands.empty()) {
ret_val = process_command_list(ctx, audio, params);
} else if (!params.prompt.empty()) {
ret_val = always_prompt_transcription(ctx, audio, params);
} else {
ret_val = process_general_transcription(ctx, audio, params);
if (!params.grammar.empty()) {
auto & grammar = params.grammar_parsed;
if (file_exists(params.grammar.c_str())) {
// read grammar from file
std::ifstream ifs(params.grammar.c_str());
const std::string txt = std::string((std::istreambuf_iterator<char>(ifs)), std::istreambuf_iterator<char>());
grammar = grammar_parser::parse(txt.c_str());
} else {
// read grammar from string
grammar = grammar_parser::parse(params.grammar.c_str());
}
// will be empty (default) if there are parse errors
if (grammar.rules.empty()) {
ret_val = 1;
} else {
fprintf(stderr, "%s: grammar:\n", __func__);
grammar_parser::print_grammar(stderr, grammar);
fprintf(stderr, "\n");
}
}
if (ret_val == 0) {
if (!params.commands.empty()) {
ret_val = process_command_list(ctx, audio, params);
} else if (!params.prompt.empty() && params.grammar_parsed.rules.empty()) {
ret_val = always_prompt_transcription(ctx, audio, params);
} else {
ret_val = process_general_transcription(ctx, audio, params);
}
}
audio.pause();

423
examples/grammar-parser.cpp Normal file
View File

@ -0,0 +1,423 @@
#include "grammar-parser.h"
#include <cstdint>
#include <cwchar>
#include <string>
#include <utility>
#include <stdexcept>
#include <exception>
namespace grammar_parser {
// NOTE: assumes valid utf8 (but checks for overrun)
// copied from whisper.cpp
std::pair<uint32_t, const char *> decode_utf8(const char * src) {
static const int lookup[] = { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 4 };
uint8_t first_byte = static_cast<uint8_t>(*src);
uint8_t highbits = first_byte >> 4;
int len = lookup[highbits];
uint8_t mask = (1 << (8 - len)) - 1;
uint32_t value = first_byte & mask;
const char * end = src + len; // may overrun!
const char * pos = src + 1;
for ( ; pos < end && *pos; pos++) {
value = (value << 6) + (static_cast<uint8_t>(*pos) & 0x3F);
}
return std::make_pair(value, pos);
}
uint32_t get_symbol_id(parse_state & state, const char * src, size_t len) {
uint32_t next_id = static_cast<uint32_t>(state.symbol_ids.size());
auto result = state.symbol_ids.insert(std::make_pair(std::string(src, len), next_id));
return result.first->second;
}
uint32_t generate_symbol_id(parse_state & state, const std::string & base_name) {
uint32_t next_id = static_cast<uint32_t>(state.symbol_ids.size());
state.symbol_ids[base_name + '_' + std::to_string(next_id)] = next_id;
return next_id;
}
void add_rule(
parse_state & state,
uint32_t rule_id,
const std::vector<whisper_grammar_element> & rule) {
if (state.rules.size() <= rule_id) {
state.rules.resize(rule_id + 1);
}
state.rules[rule_id] = rule;
}
bool is_word_char(char c) {
return ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') || c == '-' || ('0' <= c && c <= '9');
}
std::pair<uint32_t, const char *> parse_hex(const char * src, int size) {
const char * pos = src;
const char * end = src + size;
uint32_t value = 0;
for ( ; pos < end && *pos; pos++) {
value <<= 4;
char c = *pos;
if ('a' <= c && c <= 'f') {
value += c - 'a' + 10;
} else if ('A' <= c && c <= 'F') {
value += c - 'A' + 10;
} else if ('0' <= c && c <= '9') {
value += c - '0';
} else {
break;
}
}
if (pos != end) {
throw std::runtime_error("expecting " + std::to_string(size) + " hex chars at " + src);
}
return std::make_pair(value, pos);
}
const char * parse_space(const char * src, bool newline_ok) {
const char * pos = src;
while (*pos == ' ' || *pos == '\t' || *pos == '#' ||
(newline_ok && (*pos == '\r' || *pos == '\n'))) {
if (*pos == '#') {
while (*pos && *pos != '\r' && *pos != '\n') {
pos++;
}
} else {
pos++;
}
}
return pos;
}
const char * parse_name(const char * src) {
const char * pos = src;
while (is_word_char(*pos)) {
pos++;
}
if (pos == src) {
throw std::runtime_error(std::string("expecting name at ") + src);
}
return pos;
}
std::pair<uint32_t, const char *> parse_char(const char * src) {
if (*src == '\\') {
switch (src[1]) {
case 'x': return parse_hex(src + 2, 2);
case 'u': return parse_hex(src + 2, 4);
case 'U': return parse_hex(src + 2, 8);
case 't': return std::make_pair('\t', src + 2);
case 'r': return std::make_pair('\r', src + 2);
case 'n': return std::make_pair('\n', src + 2);
case '\\':
case '"':
case '[':
case ']':
return std::make_pair(src[1], src + 2);
default:
throw std::runtime_error(std::string("unknown escape at ") + src);
}
} else if (*src) {
return decode_utf8(src);
}
throw std::runtime_error("unexpected end of input");
}
const char * parse_alternates(
parse_state & state,
const char * src,
const std::string & rule_name,
uint32_t rule_id,
bool is_nested);
const char * parse_sequence(
parse_state & state,
const char * src,
const std::string & rule_name,
std::vector<whisper_grammar_element> & out_elements,
bool is_nested) {
size_t last_sym_start = out_elements.size();
const char * pos = src;
while (*pos) {
if (*pos == '"') { // literal string
pos++;
last_sym_start = out_elements.size();
while (*pos != '"') {
auto char_pair = parse_char(pos);
pos = char_pair.second;
out_elements.push_back({WHISPER_GRETYPE_CHAR, char_pair.first});
}
pos = parse_space(pos + 1, is_nested);
} else if (*pos == '[') { // char range(s)
pos++;
enum whisper_gretype start_type = WHISPER_GRETYPE_CHAR;
if (*pos == '^') {
pos++;
start_type = WHISPER_GRETYPE_CHAR_NOT;
}
last_sym_start = out_elements.size();
while (*pos != ']') {
auto char_pair = parse_char(pos);
pos = char_pair.second;
enum whisper_gretype type = last_sym_start < out_elements.size()
? WHISPER_GRETYPE_CHAR_ALT
: start_type;
out_elements.push_back({type, char_pair.first});
if (pos[0] == '-' && pos[1] != ']') {
auto endchar_pair = parse_char(pos + 1);
pos = endchar_pair.second;
out_elements.push_back({WHISPER_GRETYPE_CHAR_RNG_UPPER, endchar_pair.first});
}
}
pos = parse_space(pos + 1, is_nested);
} else if (is_word_char(*pos)) { // rule reference
const char * name_end = parse_name(pos);
uint32_t ref_rule_id = get_symbol_id(state, pos, name_end - pos);
pos = parse_space(name_end, is_nested);
last_sym_start = out_elements.size();
out_elements.push_back({WHISPER_GRETYPE_RULE_REF, ref_rule_id});
} else if (*pos == '(') { // grouping
// parse nested alternates into synthesized rule
pos = parse_space(pos + 1, true);
uint32_t sub_rule_id = generate_symbol_id(state, rule_name);
pos = parse_alternates(state, pos, rule_name, sub_rule_id, true);
last_sym_start = out_elements.size();
// output reference to synthesized rule
out_elements.push_back({WHISPER_GRETYPE_RULE_REF, sub_rule_id});
if (*pos != ')') {
throw std::runtime_error(std::string("expecting ')' at ") + pos);
}
pos = parse_space(pos + 1, is_nested);
} else if (*pos == '*' || *pos == '+' || *pos == '?') { // repetition operator
if (last_sym_start == out_elements.size()) {
throw std::runtime_error(std::string("expecting preceeding item to */+/? at ") + pos);
}
// apply transformation to previous symbol (last_sym_start to end) according to
// rewrite rules:
// S* --> S' ::= S S' |
// S+ --> S' ::= S S' | S
// S? --> S' ::= S |
uint32_t sub_rule_id = generate_symbol_id(state, rule_name);
std::vector<whisper_grammar_element> sub_rule;
// add preceding symbol to generated rule
sub_rule.insert(
sub_rule.end(), out_elements.begin() + last_sym_start, out_elements.end());
if (*pos == '*' || *pos == '+') {
// cause generated rule to recurse
sub_rule.push_back({WHISPER_GRETYPE_RULE_REF, sub_rule_id});
}
// mark start of alternate def
sub_rule.push_back({WHISPER_GRETYPE_ALT, 0});
if (*pos == '+') {
// add preceding symbol as alternate only for '+' (otherwise empty)
sub_rule.insert(
sub_rule.end(), out_elements.begin() + last_sym_start, out_elements.end());
}
sub_rule.push_back({WHISPER_GRETYPE_END, 0});
add_rule(state, sub_rule_id, sub_rule);
// in original rule, replace previous symbol with reference to generated rule
out_elements.resize(last_sym_start);
out_elements.push_back({WHISPER_GRETYPE_RULE_REF, sub_rule_id});
pos = parse_space(pos + 1, is_nested);
} else {
break;
}
}
return pos;
}
const char * parse_alternates(
parse_state & state,
const char * src,
const std::string & rule_name,
uint32_t rule_id,
bool is_nested) {
std::vector<whisper_grammar_element> rule;
const char * pos = parse_sequence(state, src, rule_name, rule, is_nested);
while (*pos == '|') {
rule.push_back({WHISPER_GRETYPE_ALT, 0});
pos = parse_space(pos + 1, true);
pos = parse_sequence(state, pos, rule_name, rule, is_nested);
}
rule.push_back({WHISPER_GRETYPE_END, 0});
add_rule(state, rule_id, rule);
return pos;
}
const char * parse_rule(parse_state & state, const char * src) {
const char * name_end = parse_name(src);
const char * pos = parse_space(name_end, false);
size_t name_len = name_end - src;
uint32_t rule_id = get_symbol_id(state, src, name_len);
const std::string name(src, name_len);
if (!(pos[0] == ':' && pos[1] == ':' && pos[2] == '=')) {
throw std::runtime_error(std::string("expecting ::= at ") + pos);
}
pos = parse_space(pos + 3, true);
pos = parse_alternates(state, pos, name, rule_id, false);
if (*pos == '\r') {
pos += pos[1] == '\n' ? 2 : 1;
} else if (*pos == '\n') {
pos++;
} else if (*pos) {
throw std::runtime_error(std::string("expecting newline or end at ") + pos);
}
return parse_space(pos, true);
}
parse_state parse(const char * src) {
try {
parse_state state;
const char * pos = parse_space(src, true);
while (*pos) {
pos = parse_rule(state, pos);
}
return state;
} catch (const std::exception & err) {
fprintf(stderr, "%s: error parsing grammar: %s\n", __func__, err.what());
return parse_state();
}
}
void print_grammar_char(FILE * file, uint32_t c) {
if (0x20 <= c && c <= 0x7f) {
fprintf(file, "%c", static_cast<char>(c));
} else {
// cop out of encoding UTF-8
fprintf(file, "<U+%04X>", c);
}
}
bool is_char_element(whisper_grammar_element elem) {
switch (elem.type) {
case WHISPER_GRETYPE_CHAR: return true;
case WHISPER_GRETYPE_CHAR_NOT: return true;
case WHISPER_GRETYPE_CHAR_ALT: return true;
case WHISPER_GRETYPE_CHAR_RNG_UPPER: return true;
default: return false;
}
}
void print_rule_binary(FILE * file, const std::vector<whisper_grammar_element> & rule) {
for (auto elem : rule) {
switch (elem.type) {
case WHISPER_GRETYPE_END: fprintf(file, "END"); break;
case WHISPER_GRETYPE_ALT: fprintf(file, "ALT"); break;
case WHISPER_GRETYPE_RULE_REF: fprintf(file, "RULE_REF"); break;
case WHISPER_GRETYPE_CHAR: fprintf(file, "CHAR"); break;
case WHISPER_GRETYPE_CHAR_NOT: fprintf(file, "CHAR_NOT"); break;
case WHISPER_GRETYPE_CHAR_RNG_UPPER: fprintf(file, "CHAR_RNG_UPPER"); break;
case WHISPER_GRETYPE_CHAR_ALT: fprintf(file, "CHAR_ALT"); break;
}
switch (elem.type) {
case WHISPER_GRETYPE_END:
case WHISPER_GRETYPE_ALT:
case WHISPER_GRETYPE_RULE_REF:
fprintf(file, "(%u) ", elem.value);
break;
case WHISPER_GRETYPE_CHAR:
case WHISPER_GRETYPE_CHAR_NOT:
case WHISPER_GRETYPE_CHAR_RNG_UPPER:
case WHISPER_GRETYPE_CHAR_ALT:
fprintf(file, "(\"");
print_grammar_char(file, elem.value);
fprintf(file, "\") ");
break;
}
}
fprintf(file, "\n");
}
void print_rule(
FILE * file,
uint32_t rule_id,
const std::vector<whisper_grammar_element> & rule,
const std::map<uint32_t, std::string> & symbol_id_names) {
if (rule.empty() || rule.back().type != WHISPER_GRETYPE_END) {
throw std::runtime_error(
"malformed rule, does not end with WHISPER_GRETYPE_END: " + std::to_string(rule_id));
}
fprintf(file, "%s ::= ", symbol_id_names.at(rule_id).c_str());
for (size_t i = 0, end = rule.size() - 1; i < end; i++) {
whisper_grammar_element elem = rule[i];
switch (elem.type) {
case WHISPER_GRETYPE_END:
throw std::runtime_error(
"unexpected end of rule: " + std::to_string(rule_id) + "," +
std::to_string(i));
case WHISPER_GRETYPE_ALT:
fprintf(file, "| ");
break;
case WHISPER_GRETYPE_RULE_REF:
fprintf(file, "%s ", symbol_id_names.at(elem.value).c_str());
break;
case WHISPER_GRETYPE_CHAR:
fprintf(file, "[");
print_grammar_char(file, elem.value);
break;
case WHISPER_GRETYPE_CHAR_NOT:
fprintf(file, "[^");
print_grammar_char(file, elem.value);
break;
case WHISPER_GRETYPE_CHAR_RNG_UPPER:
if (i == 0 || !is_char_element(rule[i - 1])) {
throw std::runtime_error(
"WHISPER_GRETYPE_CHAR_RNG_UPPER without preceding char: " +
std::to_string(rule_id) + "," + std::to_string(i));
}
fprintf(file, "-");
print_grammar_char(file, elem.value);
break;
case WHISPER_GRETYPE_CHAR_ALT:
if (i == 0 || !is_char_element(rule[i - 1])) {
throw std::runtime_error(
"WHISPER_GRETYPE_CHAR_ALT without preceding char: " +
std::to_string(rule_id) + "," + std::to_string(i));
}
print_grammar_char(file, elem.value);
break;
}
if (is_char_element(elem)) {
switch (rule[i + 1].type) {
case WHISPER_GRETYPE_CHAR_ALT:
case WHISPER_GRETYPE_CHAR_RNG_UPPER:
break;
default:
fprintf(file, "] ");
}
}
}
fprintf(file, "\n");
}
void print_grammar(FILE * file, const parse_state & state) {
try {
std::map<uint32_t, std::string> symbol_id_names;
for (auto kv : state.symbol_ids) {
symbol_id_names[kv.second] = kv.first;
}
for (size_t i = 0, end = state.rules.size(); i < end; i++) {
// fprintf(file, "%zu: ", i);
// print_rule_binary(file, state.rules[i]);
print_rule(file, uint32_t(i), state.rules[i], symbol_id_names);
// fprintf(file, "\n");
}
} catch (const std::exception & err) {
fprintf(stderr, "\n%s: error printing grammar: %s\n", __func__, err.what());
}
}
std::vector<const whisper_grammar_element *> parse_state::c_rules() const{
std::vector<const whisper_grammar_element *> ret;
for (const auto & rule : rules) {
ret.push_back(rule.data());
}
return ret;
}
}

29
examples/grammar-parser.h Normal file
View File

@ -0,0 +1,29 @@
// Implements a parser for an extended Backus-Naur form (BNF), producing the
// binary context-free grammar format specified by whisper.h. Supports character
// ranges, grouping, and repetition operators. As an example, a grammar for
// arithmetic might look like:
//
// root ::= expr
// expr ::= term ([-+*/] term)*
// term ::= num | "(" space expr ")" space
// num ::= [0-9]+ space
// space ::= [ \t\n]*
#pragma once
#include "whisper.h"
#include <vector>
#include <map>
#include <cstdint>
#include <string>
namespace grammar_parser {
struct parse_state {
std::map<std::string, uint32_t> symbol_ids;
std::vector<std::vector<whisper_grammar_element>> rules;
std::vector<const whisper_grammar_element *> c_rules() const;
};
parse_state parse(const char * src);
void print_grammar(FILE * file, const parse_state & state);
}

57
grammars/assistant.gbnf Normal file
View File

@ -0,0 +1,57 @@
# - "turn on lights."
# - "set thermostat to 22."
# - "increase TV by 10."
# - "decrease oven by 50."
# - "play music."
# - "stop podcast."
# - "schedule cleaning at 3pm."
# - "cancel cleaning."
# - "remind me to buy milk at 5pm."
# - "show me security system."
# - "hide washing machine."
# - "what is the lights status?"
# - "what is the current thermostat value?"
# - "what is the security system status?"
# - "what is the door lock status?"
# - "what is the camera battery level?"
# - "what is the weather like today?"
# - "what is the forecast for tomorrow?"
# - "what is the time?"
# - "what is my schedule for today?"
# - "what tasks do I have?"
# - "what reminders do I have?"
#
# example:
#
# ./command -m ./models/ggml-tiny.en.bin -t 8 --grammar ./grammars/assistant.gbnf --prompt "Ok Whisper, start listening for commands." --context "Whisper is a home assistant. It recognizes voice commands. Time is 11pm." --grammar-penalty 10
#
root ::= init " " (command | question) "."
prompt ::= init
# leading space is very important!
init ::= " Ok Whisper, start listening for commands."
command ::= "Turn " ("on" | "off") " " device | "Set " device " to " value |
"Increase " device " by " value | "Decrease " device " by " value |
"Play " media | "Stop " media | "Schedule " task " at " time | "Cancel " task |
"Remind me to " task " at " time | "Show me " device | "Hide " device
question ::= "What is the " device " status?" | "What is the current " device " value?" |
"What is the " device " temperature?" | "What is the " device " humidity?" |
"What is the " device " power consumption?" | "What is the " device " battery level?" |
"What is the weather like today?" | "What is the forecast for tomorrow?" |
"What is the time?" | "What is my schedule for today?" | "What tasks do I have?" |
"What reminders do I have?"
device ::= "lights" | "thermostat" | "security system" | "door lock" | "camera" | "speaker" | "TV" |
"music player" | "coffee machine" | "oven" | "refrigerator" | "washing machine" |
"vacuum cleaner"
value ::= [0-9]+
media ::= "music" | "radio" | "podcast" | "audiobook" | "TV show" | "movie"
task ::= [a-zA-Z]+ (" " [a-zA-Z]+)?
time ::= [0-9] [0-9]? ("am" | "pm")?

29
grammars/chess.gbnf Normal file
View File

@ -0,0 +1,29 @@
# - bishop to c3
# - rook to d4
# - knight to e5
# - d4 d5 knight to c3
# - c3 queen to d4 king b1
# - pawn to a1 bishop to b2 knight to c3
#
# The prompt (--prompt) is the initial phrase that the user has to say.
# This is used to prime Whisper with how the user is expected to speak.
#
# Provide long context (--context) with sample moves to help Whisper decode the correct sequence.
# Longer context is better, but it slightly increases the processing time.
#
# example:
#
# ./command -m ./models/ggml-tiny.en.bin -t 8 --grammar ./grammars/chess.gbnf --prompt "rook to b4, f3," --context "d4 d5 knight to c3, pawn to a1, bishop to b2 king e8," --grammar-penalty 100
#
root ::= init move move? move? "."
prompt ::= init "."
# leading space is very important!
init ::= " rook to b4, f3"
move ::= ", " ((piece | pawn | king) " " "to "?)? [a-h] [1-8]
piece ::= "bishop" | "rook" | "knight" | "queen"
king ::= "king"
pawn ::= "pawn"

16
grammars/colors.gbnf Normal file
View File

@ -0,0 +1,16 @@
# - red
# - green
# - blue
#
# example:
#
# ./command -m ./models/ggml-tiny.en.bin -t 8 --grammar ./grammars/colors.gbnf --prompt "red, green, blue," --context "green, red, blue,"
#
root ::= init color "."
prompt ::= init "."
# leading space is very important!
init ::= " red, green, blue"
color ::= ", " ("red" | "green" | "blue")

View File

@ -579,6 +579,25 @@ struct whisper_model {
std::map<std::string, struct ggml_tensor *> tensors;
};
struct whisper_partial_utf8 {
uint32_t value; // bit value so far (unshifted)
int n_remain; // num bytes remaining; -1 indicates invalid sequence
};
struct whisper_grammar {
/*const*/ std::vector<std::vector<whisper_grammar_element>> rules;
std::vector<std::vector<const whisper_grammar_element *>> stacks;
// buffer for partially generated UTF-8 sequence from accepted tokens
whisper_partial_utf8 partial_utf8;
};
struct whisper_grammar_candidate {
whisper_token id;
const uint32_t * code_points;
whisper_partial_utf8 partial_utf8;
};
struct whisper_sequence {
std::vector<whisper_token_data> tokens;
@ -600,6 +619,9 @@ struct whisper_decoder {
// the currently generated sequence of tokens
whisper_sequence sequence;
// grammar parse state of generated sequence of tokens
whisper_grammar grammar;
int seek_delta; // the window shift found so far based on the decoded timestamp tokens
bool failed; // has the current segment failed to decode?
@ -3685,6 +3707,425 @@ const char * whisper_print_system_info(void) {
return s.c_str();
}
//////////////////////////////////
// Grammar - ported from llama.cpp
//////////////////////////////////
// Decodes a UTF-8 string which may end in an incomplete sequence. Adds a terminating 0 for use as
// pointer. If an invalid sequence is encountered, returns `whisper_partial_utf8.n_remain == -1`.
std::pair<std::vector<uint32_t>, whisper_partial_utf8> decode_utf8(
const char * src,
whisper_partial_utf8 partial_start) {
static const int lookup[] = { 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 2, 2, 3, 4 };
const char * pos = src;
std::vector<uint32_t> code_points;
uint32_t value = partial_start.value;
int n_remain = partial_start.n_remain;
// continue previous decode, if applicable
while (*pos != 0 && n_remain > 0) {
uint8_t next_byte = static_cast<uint8_t>(*pos);
if ((next_byte >> 6) != 2) {
// invalid sequence, abort
code_points.push_back(0);
return std::make_pair(std::move(code_points), whisper_partial_utf8{ 0, -1 });
}
value = (value << 6) + (next_byte & 0x3F);
++pos;
--n_remain;
}
if (partial_start.n_remain > 0 && n_remain == 0) {
code_points.push_back(value);
}
// decode any subsequent utf-8 sequences, which may end in an incomplete one
while (*pos != 0) {
uint8_t first_byte = static_cast<uint8_t>(*pos);
uint8_t highbits = first_byte >> 4;
n_remain = lookup[highbits] - 1;
if (n_remain < 0) {
// invalid sequence, abort
code_points.clear();
code_points.push_back(0);
return std::make_pair(std::move(code_points), whisper_partial_utf8{ 0, n_remain });
}
uint8_t mask = (1 << (7 - n_remain)) - 1;
value = first_byte & mask;
++pos;
while (*pos != 0 && n_remain > 0) {
value = (value << 6) + (static_cast<uint8_t>(*pos) & 0x3F);
++pos;
--n_remain;
}
if (n_remain == 0) {
code_points.push_back(value);
}
}
code_points.push_back(0);
return std::make_pair(std::move(code_points), whisper_partial_utf8{ value, n_remain });
}
// returns true iff pos points to the end of one of the definitions of a rule
static bool whisper_grammar_is_end_of_sequence(const whisper_grammar_element * pos) {
switch (pos->type) {
case WHISPER_GRETYPE_END: return true; // NOLINT
case WHISPER_GRETYPE_ALT: return true; // NOLINT
default: return false;
}
}
// returns true iff chr satisfies the char range at pos (regular or inverse range)
// asserts that pos is pointing to a char range element
static std::pair<bool, const whisper_grammar_element *> whisper_grammar_match_char(
const whisper_grammar_element * pos,
const uint32_t chr) {
bool found = false;
bool is_positive_char = pos->type == WHISPER_GRETYPE_CHAR;
WHISPER_ASSERT(is_positive_char || pos->type == WHISPER_GRETYPE_CHAR_NOT); // NOLINT
do {
if (pos[1].type == WHISPER_GRETYPE_CHAR_RNG_UPPER) {
// inclusive range, e.g. [a-z]
found = found || (pos->value <= chr && chr <= pos[1].value);
pos += 2;
} else {
// exact char match, e.g. [a] or "a"
found = found || pos->value == chr;
pos += 1;
}
} while (pos->type == WHISPER_GRETYPE_CHAR_ALT);
return std::make_pair(found == is_positive_char, pos);
}
// returns true iff some continuation of the given partial UTF-8 sequence could satisfy the char
// range at pos (regular or inverse range)
// asserts that pos is pointing to a char range element
static bool whisper_grammar_match_partial_char(
const whisper_grammar_element * pos,
const whisper_partial_utf8 partial_utf8) {
bool is_positive_char = pos->type == WHISPER_GRETYPE_CHAR;
WHISPER_ASSERT(is_positive_char || pos->type == WHISPER_GRETYPE_CHAR_NOT);
uint32_t partial_value = partial_utf8.value;
int n_remain = partial_utf8.n_remain;
// invalid sequence or 7-bit char split across 2 bytes (overlong)
if (n_remain < 0 || (n_remain == 1 && partial_value < 2)) {
return false;
}
// range of possible code points this partial UTF-8 sequence could complete to
uint32_t low = partial_value << (n_remain * 6);
uint32_t high = low | ((1 << (n_remain * 6)) - 1);
if (low == 0) {
if (n_remain == 2) {
low = 1 << 11;
} else if (n_remain == 3) {
low = 1 << 16;
}
}
do {
if (pos[1].type == WHISPER_GRETYPE_CHAR_RNG_UPPER) {
// inclusive range, e.g. [a-z]
if (pos->value <= high && low <= pos[1].value) {
return is_positive_char;
}
pos += 2;
} else {
// exact char match, e.g. [a] or "a"
if (low <= pos->value && pos->value <= high) {
return is_positive_char;
}
pos += 1;
}
} while (pos->type == WHISPER_GRETYPE_CHAR_ALT);
return !is_positive_char;
}
// transforms a grammar pushdown stack into N possible stacks, all ending
// at a character range (terminal element)
static void whisper_grammar_advance_stack(
const std::vector<std::vector<whisper_grammar_element>> & rules,
const std::vector<const whisper_grammar_element *> & stack,
std::vector<std::vector<const whisper_grammar_element *>> & new_stacks) {
if (stack.empty()) {
new_stacks.push_back(stack);
return;
}
const whisper_grammar_element * pos = stack.back();
switch (pos->type) {
case WHISPER_GRETYPE_RULE_REF: {
const size_t rule_id = static_cast<size_t>(pos->value);
const whisper_grammar_element * subpos = rules[rule_id].data();
do {
// init new stack without the top (pos)
std::vector<const whisper_grammar_element *> new_stack(stack.begin(), stack.end() - 1);
if (!whisper_grammar_is_end_of_sequence(pos + 1)) {
// if this rule ref is followed by another element, add that to stack
new_stack.push_back(pos + 1);
}
if (!whisper_grammar_is_end_of_sequence(subpos)) {
// if alternate is nonempty, add to stack
new_stack.push_back(subpos);
}
whisper_grammar_advance_stack(rules, new_stack, new_stacks);
while (!whisper_grammar_is_end_of_sequence(subpos)) {
// scan to end of alternate def
subpos++;
}
if (subpos->type == WHISPER_GRETYPE_ALT) {
// there's another alternate def of this rule to process
subpos++;
} else {
break;
}
} while (true);
break;
}
case WHISPER_GRETYPE_CHAR:
case WHISPER_GRETYPE_CHAR_NOT:
new_stacks.push_back(stack);
break;
default:
// end of alternate (WHISPER_GRETYPE_END, WHISPER_GRETYPE_ALT) or middle of char range
// (WHISPER_GRETYPE_CHAR_ALT, WHISPER_GRETYPE_CHAR_RNG_UPPER); stack should never be left on
// those
WHISPER_ASSERT(false);
}
}
// takes a set of possible pushdown stacks on a grammar, which are required to
// be positioned at a character range (see `whisper_grammar_advance_stack`), and
// produces the N possible stacks if the given char is accepted at those
// positions
static std::vector<std::vector<const whisper_grammar_element *>> whisper_grammar_accept(
const std::vector<std::vector<whisper_grammar_element>> & rules,
const std::vector<std::vector<const whisper_grammar_element *>> & stacks,
const uint32_t chr) {
std::vector<std::vector<const whisper_grammar_element *>> new_stacks;
for (const auto & stack : stacks) {
if (stack.empty()) {
continue;
}
auto match = whisper_grammar_match_char(stack.back(), chr);
if (match.first) {
const whisper_grammar_element * pos = match.second;
// update top of stack to next element, if any
std::vector<const whisper_grammar_element *> new_stack(stack.begin(), stack.end() - 1);
if (!whisper_grammar_is_end_of_sequence(pos)) {
new_stack.push_back(pos);
}
whisper_grammar_advance_stack(rules, new_stack, new_stacks);
}
}
return new_stacks;
}
static std::vector<whisper_grammar_candidate> whisper_grammar_reject_candidates(
const std::vector<std::vector<whisper_grammar_element>> & rules,
const std::vector<std::vector<const whisper_grammar_element *>> & stacks,
const std::vector<whisper_grammar_candidate> & candidates);
static std::vector<whisper_grammar_candidate> whisper_grammar_reject_candidates_for_stack(
const std::vector<std::vector<whisper_grammar_element>> & rules,
const std::vector<const whisper_grammar_element *> & stack,
const std::vector<whisper_grammar_candidate> & candidates) {
std::vector<whisper_grammar_candidate> rejects;
if (stack.empty()) {
for (auto tok : candidates) {
if (*tok.code_points != 0 || tok.partial_utf8.n_remain != 0) {
rejects.push_back(tok);
}
}
return rejects;
}
const whisper_grammar_element * stack_pos = stack.back();
std::vector<whisper_grammar_candidate> next_candidates;
for (auto tok : candidates) {
if (*tok.code_points == 0) {
// reached end of full codepoints in token, reject iff it ended in a partial sequence
// that cannot satisfy this position in grammar
if (tok.partial_utf8.n_remain != 0 &&
!whisper_grammar_match_partial_char(stack_pos, tok.partial_utf8)) {
rejects.push_back(tok);
}
} else if (whisper_grammar_match_char(stack_pos, *tok.code_points).first) {
next_candidates.push_back({ tok.id, tok.code_points + 1, tok.partial_utf8 });
} else {
rejects.push_back(tok);
}
}
const auto * stack_pos_after = whisper_grammar_match_char(stack_pos, 0).second;
// update top of stack to next element, if any
std::vector<const whisper_grammar_element *> stack_after(stack.begin(), stack.end() - 1);
if (!whisper_grammar_is_end_of_sequence(stack_pos_after)) {
stack_after.push_back(stack_pos_after);
}
std::vector<std::vector<const whisper_grammar_element *>> next_stacks;
whisper_grammar_advance_stack(rules, stack_after, next_stacks);
auto next_rejects = whisper_grammar_reject_candidates(rules, next_stacks, next_candidates);
for (auto tok : next_rejects) {
rejects.push_back({ tok.id, tok.code_points - 1, tok.partial_utf8 });
}
return rejects;
}
static std::vector<whisper_grammar_candidate> whisper_grammar_reject_candidates(
const std::vector<std::vector<whisper_grammar_element>> & rules,
const std::vector<std::vector<const whisper_grammar_element *>> & stacks,
const std::vector<whisper_grammar_candidate> & candidates) {
if (candidates.empty() || stacks.empty()) {
return std::vector<whisper_grammar_candidate>();
}
auto rejects = whisper_grammar_reject_candidates_for_stack(rules, stacks.front(), candidates);
for (size_t i = 1, size = stacks.size(); i < size; ++i) {
rejects = whisper_grammar_reject_candidates_for_stack(rules, stacks[i], rejects);
}
return rejects;
}
static struct whisper_grammar whisper_grammar_init(
const whisper_grammar_element ** rules,
size_t n_rules,
size_t i_start_rule) {
const whisper_grammar_element * pos;
// copy rule definitions into vectors
std::vector<std::vector<whisper_grammar_element>> vec_rules(n_rules);
for (size_t i = 0; i < n_rules; i++) {
for (pos = rules[i]; pos->type != WHISPER_GRETYPE_END; pos++) {
vec_rules[i].push_back(*pos);
}
vec_rules[i].push_back({WHISPER_GRETYPE_END, 0});
}
// loop over alternates of start rule to build initial stacks
std::vector<std::vector<const whisper_grammar_element *>> stacks;
pos = rules[i_start_rule];
do {
std::vector<const whisper_grammar_element *> stack;
if (!whisper_grammar_is_end_of_sequence(pos)) {
// if alternate is nonempty, add to stack
stack.push_back(pos);
}
whisper_grammar_advance_stack(vec_rules, stack, stacks);
while (!whisper_grammar_is_end_of_sequence(pos)) {
// scan to end of alternate def
pos++;
}
if (pos->type == WHISPER_GRETYPE_ALT) {
// there's another alternate def of this rule to process
pos++;
} else {
break;
}
} while (true);
return { std::move(vec_rules), std::move(stacks), {} };
}
static void whisper_suppress_invalid_grammar(
whisper_context & ctx,
const whisper_full_params & params,
std::vector<float> & logits,
const whisper_grammar & grammar) {
if (grammar.rules.empty() || grammar.stacks.empty()) {
return;
}
//bool allow_eot = false;
//for (const auto & stack : grammar.stacks) {
// if (stack.empty()) {
// allow_eot = true;
// break;
// }
//}
const whisper_token eot = whisper_token_eot(&ctx);
std::vector<std::pair<std::vector<uint32_t>, whisper_partial_utf8>> candidates_decoded;
std::vector<whisper_grammar_candidate> candidates_grammar;
for (whisper_token id = 0; id < eot; ++id) {
const std::string & text = ctx.vocab.id_to_token[id];
if (!text.empty()) {
candidates_decoded.push_back(decode_utf8(text.c_str(), grammar.partial_utf8));
candidates_grammar.push_back({ id, candidates_decoded.back().first.data(), candidates_decoded.back().second });
}
}
const auto rejects = whisper_grammar_reject_candidates(grammar.rules, grammar.stacks, candidates_grammar);
for (const auto & reject : rejects) {
logits[reject.id] -= params.grammar_penalty;
}
// when the grammar allows a continuation, we penalize the end-of-text token
//if (!allow_eot) {
// logits[eot] -= params.grammar_penalty;
//}
//fprintf(stderr, "Allowed: (%zu tokens)\n", size - rejects.size());
}
static void whisper_grammar_accept_token(whisper_context & ctx, whisper_grammar & grammar, whisper_token token) {
if (grammar.rules.empty() || grammar.stacks.empty()) {
return;
}
//fprintf(stderr, "Accept: '%s'\n", ctx.vocab.id_to_token[token].c_str());
const std::string & text = ctx.vocab.id_to_token[token];
if (text.rfind("[_", 0) == 0) {
// fprintf(stderr, " (skipped)\n");
return;
}
// fprintf(stderr, "\n");
// Note terminating 0 in decoded string
const auto decoded = decode_utf8(text.c_str(), grammar.partial_utf8);
const auto & code_points = decoded.first;
for (auto it = code_points.begin(), end = code_points.end() - 1; it != end; ++it) {
grammar.stacks = whisper_grammar_accept(grammar.rules, grammar.stacks, *it);
}
grammar.partial_utf8 = decoded.second;
}
//////////////
// END grammar
//////////////
////////////////////////////////////////////////////////////////////////////
struct whisper_context_params * whisper_context_default_params_by_ref() {
@ -3714,6 +4155,7 @@ struct whisper_full_params whisper_full_default_params(enum whisper_sampling_str
/*.translate =*/ false,
/*.no_context =*/ true,
/*.no_timestamps =*/ false,
/*.single_segment =*/ false,
/*.print_special =*/ false,
/*.print_progress =*/ true,
@ -3776,6 +4218,11 @@ struct whisper_full_params whisper_full_default_params(enum whisper_sampling_str
/*.logits_filter_callback =*/ nullptr,
/*.logits_filter_callback_user_data =*/ nullptr,
/*.grammar_rules =*/ nullptr,
/*.n_grammar_rules =*/ 0,
/*.i_start_rule =*/ 0,
/*.grammar_penalty =*/ 100.0f,
};
switch (strategy) {
@ -3927,6 +4374,11 @@ static void whisper_process_logits(
// suppress <|notimestamps|> token
// ref: https://github.com/openai/whisper/blob/0b1ba3d46ebf7fe6f953acfd8cad62a4f851b49f/whisper/decoding.py#L410-L412
logits[vocab.token_not] = -INFINITY;
if (params.no_timestamps) {
for (int i = vocab.token_beg; i < n_logits; ++i) {
logits[i] = -INFINITY;
}
}
// suppress sot and nosp tokens
logits[vocab.token_sot] = -INFINITY;
@ -3942,6 +4394,14 @@ static void whisper_process_logits(
logits[vocab.token_transcribe] = -INFINITY;
logits[vocab.token_prev] = -INFINITY;
// suppress lang tokens
for (size_t i = 0; i < g_lang.size(); ++i) {
logits[whisper_token_lang(&ctx, i)] = -INFINITY;
}
// suppress prev token
logits[vocab.token_prev] = -INFINITY;
if (params.logits_filter_callback) {
params.logits_filter_callback(&ctx, &state, tokens_cur.data(), tokens_cur.size(), logits.data(), params.logits_filter_callback_user_data);
}
@ -4052,10 +4512,33 @@ static void whisper_process_logits(
//WHISPER_LOG_INFO("timestamp_logprob=%f max_text_token_logprob=%f\n", timestamp_logprob, max_text_token_logprob);
if (timestamp_logprob > max_text_token_logprob) {
//printf("sampling timestamp\n");
for (int i = 0; i < vocab.token_beg; ++i) {
logits[i] = -INFINITY;
logprobs[i] = -INFINITY;
}
} else if (params.n_grammar_rules > 0) {
whisper_suppress_invalid_grammar(ctx, params, logits, decoder.grammar);
// populate the logprobs array (log_softmax)
{
const float logit_max = *std::max_element(logits.begin(), logits.end());
float logsumexp = 0.0f;
for (int i = 0; i < n_logits; ++i) {
if (logits[i] > -INFINITY) {
logsumexp += expf(logits[i] - logit_max);
}
}
logsumexp = logf(logsumexp) + logit_max;
for (int i = 0; i < n_logits; ++i) {
if (logits[i] > -INFINITY) {
logprobs[i] = logits[i] - logsumexp;
} else {
logprobs[i] = -INFINITY;
}
}
}
}
}
}
@ -4073,32 +4556,55 @@ static void whisper_process_logits(
#if 0
// print first 100 logits - token string : logit
for (int i = 0; i < 100; i++) {
const auto token = vocab.id_to_token.at(i);
const auto prob = probs[i];
const auto logit = logits[i];
const auto logprob = logprobs[i];
printf("%s : prob=%9.5f logit=%9.5f logprob=%9.5f\n", token.c_str(), prob, logit, logprob);
//for (int i = 0; i < 10; i++) {
// const auto token = vocab.id_to_token.at(i);
// const auto prob = probs[i];
// const auto logit = logits[i];
// const auto logprob = logprobs[i];
// printf("%16s : prob=%9.5f logit=%9.5f logprob=%9.5f\n", token.c_str(), prob, logit, logprob);
//}
// print sorted
{
std::vector<std::pair<float, int>> pairs;
for (int i = 0; i < n_logits; ++i) {
pairs.push_back(std::make_pair(probs[i], i));
}
std::sort(pairs.begin(), pairs.end(), [](const std::pair<float, int>& a, const std::pair<float, int>& b) {
return a.first > b.first;
});
for (int i = 0; i < 10; i++) {
const auto token = vocab.id_to_token.at(pairs[i].second);
const auto prob = pairs[i].first;
const auto logit = logits[pairs[i].second];
const auto logprob = logprobs[pairs[i].second];
printf("%16s : id=%6d prob=%9.5f logit=%9.5f logprob=%9.5f '%s'\n", token.c_str(), pairs[i].second, prob, logit, logprob, token.c_str());
}
printf("----------------\n");
}
// "And", "and", " And", " and"
printf("logits[\"and\"] = %f\n", logits[vocab.token_to_id.at("and")]);
printf("logits[\"And\"] = %f\n", logits[vocab.token_to_id.at("And")]);
printf("logits[\" and\"] = %f\n", logits[vocab.token_to_id.at(" and")]);
printf("logits[\" And\"] = %f\n", logits[vocab.token_to_id.at(" And")]);
printf("logits[\" so\"] = %f\n", logits[vocab.token_to_id.at(" so")]);
//printf("logits[\"and\"] = %f\n", logits[vocab.token_to_id.at("and")]);
//printf("logits[\"And\"] = %f\n", logits[vocab.token_to_id.at("And")]);
//printf("logits[\" and\"] = %f\n", logits[vocab.token_to_id.at(" and")]);
//printf("logits[\" And\"] = %f\n", logits[vocab.token_to_id.at(" And")]);
//printf("logits[\" so\"] = %f\n", logits[vocab.token_to_id.at(" so")]);
printf("logprobs[\"and\"] = %f\n", logprobs[vocab.token_to_id.at("and")]);
printf("logprobs[\"And\"] = %f\n", logprobs[vocab.token_to_id.at("And")]);
printf("logprobs[\" and\"] = %f\n", logprobs[vocab.token_to_id.at(" and")]);
printf("logprobs[\" And\"] = %f\n", logprobs[vocab.token_to_id.at(" And")]);
printf("logprobs[\" so\"] = %f\n", logprobs[vocab.token_to_id.at(" so")]);
//printf("logprobs[\"and\"] = %f\n", logprobs[vocab.token_to_id.at("and")]);
//printf("logprobs[\"And\"] = %f\n", logprobs[vocab.token_to_id.at("And")]);
//printf("logprobs[\" and\"] = %f\n", logprobs[vocab.token_to_id.at(" and")]);
//printf("logprobs[\" And\"] = %f\n", logprobs[vocab.token_to_id.at(" And")]);
//printf("logprobs[\" so\"] = %f\n", logprobs[vocab.token_to_id.at(" so")]);
printf("probs[\"and\"] = %f\n", probs[vocab.token_to_id.at("and")]);
printf("probs[\"And\"] = %f\n", probs[vocab.token_to_id.at("And")]);
printf("probs[\" and\"] = %f\n", probs[vocab.token_to_id.at(" and")]);
printf("probs[\" And\"] = %f\n", probs[vocab.token_to_id.at(" And")]);
printf("probs[\" so\"] = %f\n", probs[vocab.token_to_id.at(" so")]);
//printf("probs[\"and\"] = %f\n", probs[vocab.token_to_id.at("and")]);
//printf("probs[\"And\"] = %f\n", probs[vocab.token_to_id.at("And")]);
//printf("probs[\" and\"] = %f\n", probs[vocab.token_to_id.at(" and")]);
//printf("probs[\" And\"] = %f\n", probs[vocab.token_to_id.at(" And")]);
//printf("probs[\" so\"] = %f\n", probs[vocab.token_to_id.at(" so")]);
#endif
}
@ -4223,8 +4729,11 @@ static std::vector<whisper_token_data> whisper_sample_token_topk(
ptsum = sum_ts;
}
std::discrete_distribution<> dist(probs.begin(), probs.end());
for (int i = 0; i < k; ++i) {
const auto id = logits_id[i].second;
const auto id = dist(state.rng);
//printf("XXX %d %d %f %f %f %f\n", id, tid, probs[id], logprobs[id], pt, ptsum);
result.push_back({ id, tid, probs[id], logprobs[id], pt, ptsum, -1, -1, 0.0f, });
@ -4553,7 +5062,7 @@ int whisper_full_with_state(
state->exp_n_audio_ctx = params.audio_ctx;
// these tokens determine the task that will be performed
std::vector<whisper_token> prompt_init = { whisper_token_sot(ctx) };
std::vector<whisper_token> prompt_init = { whisper_token_sot(ctx), };
if (whisper_is_multilingual(ctx)) {
const int lang_id = whisper_lang_id(params.language);
@ -4566,17 +5075,19 @@ int whisper_full_with_state(
}
}
// distilled models require the "no_timestamps" token
{
const bool is_distil = ctx->model.hparams.n_text_layer == 2;
// distilled models require the "no_timestamps" token
// TODO: add input parameter (#1229)
if (is_distil) {
if (is_distil && !params.no_timestamps) {
WHISPER_LOG_WARN("%s: using distilled model - forcing no_timestamps\n", __func__);
prompt_init.push_back(whisper_token_not(ctx));
params.no_timestamps = true;
}
}
if (params.no_timestamps) {
prompt_init.push_back(whisper_token_not(ctx));
}
int seek = seek_start;
std::vector<whisper_token> prompt;
@ -4652,7 +5163,7 @@ int whisper_full_with_state(
n_decoders_cur = std::max(1, n_decoders_cur);
WHISPER_PRINT_DEBUG("\n%s: decoding with %d decoders, temperature = %.2f\n", __func__, n_decoders_cur, t_cur);
WHISPER_PRINT_DEBUG("\n%s: strategy = %d, decoding with %d decoders, temperature = %.2f\n", __func__, params.strategy, n_decoders_cur, t_cur);
// TAGS: WHISPER_DECODER_INIT
for (int j = 0; j < n_decoders_cur; ++j) {
@ -4673,6 +5184,13 @@ int whisper_full_with_state(
decoder.failed = false;
decoder.completed = false;
decoder.has_ts = false;
if (params.grammar_rules != nullptr) {
decoder.grammar = whisper_grammar_init(
params.grammar_rules, params.n_grammar_rules, params.i_start_rule);
} else {
decoder.grammar = {};
}
}
// init prompt and kv cache for the current iteration
@ -4790,6 +5308,10 @@ int whisper_full_with_state(
continue;
}
if (cur_c >= beam_candidates.size()) {
cur_c = 0;
}
auto & cur = beam_candidates[cur_c++];
while (beam_candidates.size() > cur_c && beam_candidates[cur_c].sequence.sum_logprobs_all == cur.sequence.sum_logprobs_all && i > 0) {
@ -4844,6 +5366,8 @@ int whisper_full_with_state(
has_ts = true;
}
whisper_grammar_accept_token(*ctx, decoder.grammar, token.id);
#ifdef WHISPER_DEBUG
{
const auto tt = token.pt > 0.10 ? ctx->vocab.id_to_token.at(token.tid) : "[?]";

View File

@ -109,6 +109,37 @@ extern "C" {
void (*close)(void * ctx);
} whisper_model_loader;
// grammar element type
enum whisper_gretype {
// end of rule definition
WHISPER_GRETYPE_END = 0,
// start of alternate definition for rule
WHISPER_GRETYPE_ALT = 1,
// non-terminal element: reference to rule
WHISPER_GRETYPE_RULE_REF = 2,
// terminal element: character (code point)
WHISPER_GRETYPE_CHAR = 3,
// inverse char(s) ([^a], [^a-b] [^abc])
WHISPER_GRETYPE_CHAR_NOT = 4,
// modifies a preceding WHISPER_GRETYPE_CHAR or LLAMA_GRETYPE_CHAR_ALT to
// be an inclusive range ([a-z])
WHISPER_GRETYPE_CHAR_RNG_UPPER = 5,
// modifies a preceding WHISPER_GRETYPE_CHAR or
// WHISPER_GRETYPE_CHAR_RNG_UPPER to add an alternate char to match ([ab], [a-zA])
WHISPER_GRETYPE_CHAR_ALT = 6,
};
typedef struct whisper_grammar_element {
enum whisper_gretype type;
uint32_t value; // Unicode code point or rule ID
} whisper_grammar_element;
// Various functions for loading a ggml whisper model.
// Allocate (almost) all memory needed for the model.
// Return NULL on failure
@ -402,6 +433,7 @@ extern "C" {
bool translate;
bool no_context; // do not use past transcription (if any) as initial prompt for the decoder
bool no_timestamps; // do not generate timestamps
bool single_segment; // force single segment output (useful for streaming)
bool print_special; // print special tokens (e.g. <SOT>, <EOT>, <BEG>, etc.)
bool print_progress; // print progress information
@ -479,6 +511,11 @@ extern "C" {
// called by each decoder to filter obtained logits
whisper_logits_filter_callback logits_filter_callback;
void * logits_filter_callback_user_data;
const whisper_grammar_element ** grammar_rules;
size_t n_grammar_rules;
size_t i_start_rule;
float grammar_penalty;
};
// NOTE: this function allocates memory, and it is the responsibility of the caller to free the pointer - see whisper_free_context_params & whisper_free_params()