diff options
Diffstat (limited to 'ffmpeg/libavcodec/flac_parser.c')
| -rw-r--r-- | ffmpeg/libavcodec/flac_parser.c | 724 |
1 files changed, 0 insertions, 724 deletions
diff --git a/ffmpeg/libavcodec/flac_parser.c b/ffmpeg/libavcodec/flac_parser.c deleted file mode 100644 index ba1f060..0000000 --- a/ffmpeg/libavcodec/flac_parser.c +++ /dev/null @@ -1,724 +0,0 @@ -/* - * FLAC parser - * Copyright (c) 2010 Michael Chinen - * - * This file is part of FFmpeg. - * - * FFmpeg is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * FFmpeg is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with FFmpeg; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - */ - -/** - * @file - * FLAC parser - * - * The FLAC parser buffers input until FLAC_MIN_HEADERS has been found. - * Each time it finds and verifies a CRC-8 header it sees which of the - * FLAC_MAX_SEQUENTIAL_HEADERS that came before it have a valid CRC-16 footer - * that ends at the newly found header. - * Headers are scored by FLAC_HEADER_BASE_SCORE plus the max of its crc-verified - * children, penalized by changes in sample rate, frame number, etc. - * The parser returns the frame with the highest score. - **/ - -#include "libavutil/attributes.h" -#include "libavutil/crc.h" -#include "libavutil/fifo.h" -#include "bytestream.h" -#include "parser.h" -#include "flac.h" - -/** maximum number of adjacent headers that compare CRCs against each other */ -#define FLAC_MAX_SEQUENTIAL_HEADERS 3 -/** minimum number of headers buffered and checked before returning frames */ -#define FLAC_MIN_HEADERS 10 -/** estimate for average size of a FLAC frame */ -#define FLAC_AVG_FRAME_SIZE 8192 - -/** scoring settings for score_header */ -#define FLAC_HEADER_BASE_SCORE 10 -#define FLAC_HEADER_CHANGED_PENALTY 7 -#define FLAC_HEADER_CRC_FAIL_PENALTY 50 -#define FLAC_HEADER_NOT_PENALIZED_YET 100000 -#define FLAC_HEADER_NOT_SCORED_YET -100000 - -/** largest possible size of flac header */ -#define MAX_FRAME_HEADER_SIZE 16 - -typedef struct FLACHeaderMarker { - int offset; /**< byte offset from start of FLACParseContext->buffer */ - int *link_penalty; /**< pointer to array of local scores between this header - and the one at a distance equal array position */ - int max_score; /**< maximum score found after checking each child that - has a valid CRC */ - FLACFrameInfo fi; /**< decoded frame header info */ - struct FLACHeaderMarker *next; /**< next CRC-8 verified header that - immediately follows this one in - the bytestream */ - struct FLACHeaderMarker *best_child; /**< following frame header with - which this frame has the best - score with */ -} FLACHeaderMarker; - -typedef struct FLACParseContext { - AVCodecParserContext *pc; /**< parent context */ - AVCodecContext *avctx; /**< codec context pointer for logging */ - FLACHeaderMarker *headers; /**< linked-list that starts at the first - CRC-8 verified header within buffer */ - FLACHeaderMarker *best_header; /**< highest scoring header within buffer */ - int nb_headers_found; /**< number of headers found in the last - flac_parse() call */ - int nb_headers_buffered; /**< number of headers that are buffered */ - int best_header_valid; /**< flag set when the parser returns junk; - if set return best_header next time */ - AVFifoBuffer *fifo_buf; /**< buffer to store all data until headers - can be verified */ - int end_padded; /**< specifies if fifo_buf's end is padded */ - uint8_t *wrap_buf; /**< general fifo read buffer when wrapped */ - int wrap_buf_allocated_size; /**< actual allocated size of the buffer */ - FLACFrameInfo last_fi; /**< last decoded frame header info */ - int last_fi_valid; /**< set if last_fi is valid */ -} FLACParseContext; - -static int frame_header_is_valid(AVCodecContext *avctx, const uint8_t *buf, - FLACFrameInfo *fi) -{ - GetBitContext gb; - init_get_bits(&gb, buf, MAX_FRAME_HEADER_SIZE * 8); - return !ff_flac_decode_frame_header(avctx, &gb, fi, 127); -} - -/** - * Non-destructive fast fifo pointer fetching - * Returns a pointer from the specified offset. - * If possible the pointer points within the fifo buffer. - * Otherwise (if it would cause a wrap around,) a pointer to a user-specified - * buffer is used. - * The pointer can be NULL. In any case it will be reallocated to hold the size. - * If the returned pointer will be used after subsequent calls to flac_fifo_read_wrap - * then the subsequent calls should pass in a different wrap_buf so as to not - * overwrite the contents of the previous wrap_buf. - * This function is based on av_fifo_generic_read, which is why there is a comment - * about a memory barrier for SMP. - */ -static uint8_t* flac_fifo_read_wrap(FLACParseContext *fpc, int offset, int len, - uint8_t** wrap_buf, int* allocated_size) -{ - AVFifoBuffer *f = fpc->fifo_buf; - uint8_t *start = f->rptr + offset; - uint8_t *tmp_buf; - - if (start >= f->end) - start -= f->end - f->buffer; - if (f->end - start >= len) - return start; - - tmp_buf = av_fast_realloc(*wrap_buf, allocated_size, len); - - if (!tmp_buf) { - av_log(fpc->avctx, AV_LOG_ERROR, - "couldn't reallocate wrap buffer of size %d", len); - return NULL; - } - *wrap_buf = tmp_buf; - do { - int seg_len = FFMIN(f->end - start, len); - memcpy(tmp_buf, start, seg_len); - tmp_buf = (uint8_t*)tmp_buf + seg_len; -// memory barrier needed for SMP here in theory - - start += seg_len - (f->end - f->buffer); - len -= seg_len; - } while (len > 0); - - return *wrap_buf; -} - -/** - * Return a pointer in the fifo buffer where the offset starts at until - * the wrap point or end of request. - * len will contain the valid length of the returned buffer. - * A second call to flac_fifo_read (with new offset and len) should be called - * to get the post-wrap buf if the returned len is less than the requested. - **/ -static uint8_t* flac_fifo_read(FLACParseContext *fpc, int offset, int *len) -{ - AVFifoBuffer *f = fpc->fifo_buf; - uint8_t *start = f->rptr + offset; - - if (start >= f->end) - start -= f->end - f->buffer; - *len = FFMIN(*len, f->end - start); - return start; -} - -static int find_headers_search_validate(FLACParseContext *fpc, int offset) -{ - FLACFrameInfo fi; - uint8_t *header_buf; - int size = 0; - header_buf = flac_fifo_read_wrap(fpc, offset, - MAX_FRAME_HEADER_SIZE, - &fpc->wrap_buf, - &fpc->wrap_buf_allocated_size); - if (frame_header_is_valid(fpc->avctx, header_buf, &fi)) { - FLACHeaderMarker **end_handle = &fpc->headers; - int i; - - size = 0; - while (*end_handle) { - end_handle = &(*end_handle)->next; - size++; - } - - *end_handle = av_mallocz(sizeof(FLACHeaderMarker)); - if (!*end_handle) { - av_log(fpc->avctx, AV_LOG_ERROR, - "couldn't allocate FLACHeaderMarker\n"); - return AVERROR(ENOMEM); - } - (*end_handle)->fi = fi; - (*end_handle)->offset = offset; - (*end_handle)->link_penalty = av_malloc(sizeof(int) * - FLAC_MAX_SEQUENTIAL_HEADERS); - for (i = 0; i < FLAC_MAX_SEQUENTIAL_HEADERS; i++) - (*end_handle)->link_penalty[i] = FLAC_HEADER_NOT_PENALIZED_YET; - - fpc->nb_headers_found++; - size++; - } - return size; -} - -static int find_headers_search(FLACParseContext *fpc, uint8_t *buf, int buf_size, - int search_start) - -{ - int size = 0, mod_offset = (buf_size - 1) % 4, i, j; - uint32_t x; - - for (i = 0; i < mod_offset; i++) { - if ((AV_RB16(buf + i) & 0xFFFE) == 0xFFF8) - size = find_headers_search_validate(fpc, search_start + i); - } - - for (; i < buf_size - 1; i += 4) { - x = AV_RB32(buf + i); - if (((x & ~(x + 0x01010101)) & 0x80808080)) { - for (j = 0; j < 4; j++) { - if ((AV_RB16(buf + i + j) & 0xFFFE) == 0xFFF8) - size = find_headers_search_validate(fpc, search_start + i + j); - } - } - } - return size; -} - -static int find_new_headers(FLACParseContext *fpc, int search_start) -{ - FLACHeaderMarker *end; - int search_end, size = 0, read_len, temp; - uint8_t *buf; - fpc->nb_headers_found = 0; - - /* Search for a new header of at most 16 bytes. */ - search_end = av_fifo_size(fpc->fifo_buf) - (MAX_FRAME_HEADER_SIZE - 1); - read_len = search_end - search_start + 1; - buf = flac_fifo_read(fpc, search_start, &read_len); - size = find_headers_search(fpc, buf, read_len, search_start); - search_start += read_len - 1; - - /* If fifo end was hit do the wrap around. */ - if (search_start != search_end) { - uint8_t wrap[2]; - - wrap[0] = buf[read_len - 1]; - read_len = search_end - search_start + 1; - - /* search_start + 1 is the post-wrap offset in the fifo. */ - buf = flac_fifo_read(fpc, search_start + 1, &read_len); - wrap[1] = buf[0]; - - if ((AV_RB16(wrap) & 0xFFFE) == 0xFFF8) { - temp = find_headers_search_validate(fpc, search_start); - size = FFMAX(size, temp); - } - search_start++; - - /* Continue to do the last half of the wrap. */ - temp = find_headers_search(fpc, buf, read_len, search_start); - size = FFMAX(size, temp); - search_start += read_len - 1; - } - - /* Return the size even if no new headers were found. */ - if (!size && fpc->headers) - for (end = fpc->headers; end; end = end->next) - size++; - return size; -} - -static int check_header_fi_mismatch(FLACParseContext *fpc, - FLACFrameInfo *header_fi, - FLACFrameInfo *child_fi, - int log_level_offset) -{ - int deduction = 0; - if (child_fi->samplerate != header_fi->samplerate) { - deduction += FLAC_HEADER_CHANGED_PENALTY; - av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset, - "sample rate change detected in adjacent frames\n"); - } - if (child_fi->bps != header_fi->bps) { - deduction += FLAC_HEADER_CHANGED_PENALTY; - av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset, - "bits per sample change detected in adjacent frames\n"); - } - if (child_fi->is_var_size != header_fi->is_var_size) { - /* Changing blocking strategy not allowed per the spec */ - deduction += FLAC_HEADER_BASE_SCORE; - av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset, - "blocking strategy change detected in adjacent frames\n"); - } - if (child_fi->channels != header_fi->channels) { - deduction += FLAC_HEADER_CHANGED_PENALTY; - av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset, - "number of channels change detected in adjacent frames\n"); - } - return deduction; -} - -static int check_header_mismatch(FLACParseContext *fpc, - FLACHeaderMarker *header, - FLACHeaderMarker *child, - int log_level_offset) -{ - FLACFrameInfo *header_fi = &header->fi, *child_fi = &child->fi; - int deduction, deduction_expected = 0, i; - deduction = check_header_fi_mismatch(fpc, header_fi, child_fi, - log_level_offset); - /* Check sample and frame numbers. */ - if ((child_fi->frame_or_sample_num - header_fi->frame_or_sample_num - != header_fi->blocksize) && - (child_fi->frame_or_sample_num - != header_fi->frame_or_sample_num + 1)) { - FLACHeaderMarker *curr; - int expected_frame_num, expected_sample_num; - /* If there are frames in the middle we expect this deduction, - as they are probably valid and this one follows it */ - - expected_frame_num = expected_sample_num = header_fi->frame_or_sample_num; - curr = header; - while (curr != child) { - /* Ignore frames that failed all crc checks */ - for (i = 0; i < FLAC_MAX_SEQUENTIAL_HEADERS; i++) { - if (curr->link_penalty[i] < FLAC_HEADER_CRC_FAIL_PENALTY) { - expected_frame_num++; - expected_sample_num += curr->fi.blocksize; - break; - } - } - curr = curr->next; - } - - if (expected_frame_num == child_fi->frame_or_sample_num || - expected_sample_num == child_fi->frame_or_sample_num) - deduction_expected = deduction ? 0 : 1; - - deduction += FLAC_HEADER_CHANGED_PENALTY; - av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset, - "sample/frame number mismatch in adjacent frames\n"); - } - - /* If we have suspicious headers, check the CRC between them */ - if (deduction && !deduction_expected) { - FLACHeaderMarker *curr; - int read_len; - uint8_t *buf; - uint32_t crc = 1; - int inverted_test = 0; - - /* Since CRC is expensive only do it if we haven't yet. - This assumes a CRC penalty is greater than all other check penalties */ - curr = header->next; - for (i = 0; i < FLAC_MAX_SEQUENTIAL_HEADERS && curr != child; i++) - curr = curr->next; - - if (header->link_penalty[i] < FLAC_HEADER_CRC_FAIL_PENALTY || - header->link_penalty[i] == FLAC_HEADER_NOT_PENALIZED_YET) { - FLACHeaderMarker *start, *end; - - /* Although overlapping chains are scored, the crc should never - have to be computed twice for a single byte. */ - start = header; - end = child; - if (i > 0 && - header->link_penalty[i - 1] >= FLAC_HEADER_CRC_FAIL_PENALTY) { - while (start->next != child) - start = start->next; - inverted_test = 1; - } else if (i > 0 && - header->next->link_penalty[i-1] >= - FLAC_HEADER_CRC_FAIL_PENALTY ) { - end = header->next; - inverted_test = 1; - } - - read_len = end->offset - start->offset; - buf = flac_fifo_read(fpc, start->offset, &read_len); - crc = av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, buf, read_len); - read_len = (end->offset - start->offset) - read_len; - - if (read_len) { - buf = flac_fifo_read(fpc, end->offset - read_len, &read_len); - crc = av_crc(av_crc_get_table(AV_CRC_16_ANSI), crc, buf, read_len); - } - } - - if (!crc ^ !inverted_test) { - deduction += FLAC_HEADER_CRC_FAIL_PENALTY; - av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset, - "crc check failed from offset %i (frame %"PRId64") to %i (frame %"PRId64")\n", - header->offset, header_fi->frame_or_sample_num, - child->offset, child_fi->frame_or_sample_num); - } - } - return deduction; -} - -/** - * Score a header. - * - * Give FLAC_HEADER_BASE_SCORE points to a frame for existing. - * If it has children, (subsequent frames of which the preceding CRC footer - * validates against this one,) then take the maximum score of the children, - * with a penalty of FLAC_HEADER_CHANGED_PENALTY applied for each change to - * bps, sample rate, channels, but not decorrelation mode, or blocksize, - * because it can change often. - **/ -static int score_header(FLACParseContext *fpc, FLACHeaderMarker *header) -{ - FLACHeaderMarker *child; - int dist = 0; - int child_score; - int base_score = FLAC_HEADER_BASE_SCORE; - if (header->max_score != FLAC_HEADER_NOT_SCORED_YET) - return header->max_score; - - /* Modify the base score with changes from the last output header */ - if (fpc->last_fi_valid) { - /* Silence the log since this will be repeated if selected */ - base_score -= check_header_fi_mismatch(fpc, &fpc->last_fi, &header->fi, - AV_LOG_DEBUG); - } - - header->max_score = base_score; - - /* Check and compute the children's scores. */ - child = header->next; - for (dist = 0; dist < FLAC_MAX_SEQUENTIAL_HEADERS && child; dist++) { - /* Look at the child's frame header info and penalize suspicious - changes between the headers. */ - if (header->link_penalty[dist] == FLAC_HEADER_NOT_PENALIZED_YET) { - header->link_penalty[dist] = check_header_mismatch(fpc, header, - child, AV_LOG_DEBUG); - } - child_score = score_header(fpc, child) - header->link_penalty[dist]; - - if (FLAC_HEADER_BASE_SCORE + child_score > header->max_score) { - /* Keep the child because the frame scoring is dynamic. */ - header->best_child = child; - header->max_score = base_score + child_score; - } - child = child->next; - } - - return header->max_score; -} - -static void score_sequences(FLACParseContext *fpc) -{ - FLACHeaderMarker *curr; - int best_score = 0;//FLAC_HEADER_NOT_SCORED_YET; - /* First pass to clear all old scores. */ - for (curr = fpc->headers; curr; curr = curr->next) - curr->max_score = FLAC_HEADER_NOT_SCORED_YET; - - /* Do a second pass to score them all. */ - for (curr = fpc->headers; curr; curr = curr->next) { - if (score_header(fpc, curr) > best_score) { - fpc->best_header = curr; - best_score = curr->max_score; - } - } -} - -static int get_best_header(FLACParseContext* fpc, const uint8_t **poutbuf, - int *poutbuf_size) -{ - FLACHeaderMarker *header = fpc->best_header; - FLACHeaderMarker *child = header->best_child; - if (!child) { - *poutbuf_size = av_fifo_size(fpc->fifo_buf) - header->offset; - } else { - *poutbuf_size = child->offset - header->offset; - - /* If the child has suspicious changes, log them */ - check_header_mismatch(fpc, header, child, 0); - } - - if (header->fi.channels != fpc->avctx->channels || - !fpc->avctx->channel_layout) { - fpc->avctx->channels = header->fi.channels; - ff_flac_set_channel_layout(fpc->avctx); - } - fpc->avctx->sample_rate = header->fi.samplerate; - fpc->pc->duration = header->fi.blocksize; - *poutbuf = flac_fifo_read_wrap(fpc, header->offset, *poutbuf_size, - &fpc->wrap_buf, - &fpc->wrap_buf_allocated_size); - - fpc->best_header_valid = 0; - fpc->last_fi_valid = 1; - fpc->last_fi = header->fi; - - /* Return the negative overread index so the client can compute pos. - This should be the amount overread to the beginning of the child */ - if (child) - return child->offset - av_fifo_size(fpc->fifo_buf); - return 0; -} - -static int flac_parse(AVCodecParserContext *s, AVCodecContext *avctx, - const uint8_t **poutbuf, int *poutbuf_size, - const uint8_t *buf, int buf_size) -{ - FLACParseContext *fpc = s->priv_data; - FLACHeaderMarker *curr; - int nb_headers; - const uint8_t *read_end = buf; - const uint8_t *read_start = buf; - - if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { - FLACFrameInfo fi; - if (frame_header_is_valid(avctx, buf, &fi)) { - s->duration = fi.blocksize; - if (!avctx->sample_rate) - avctx->sample_rate = fi.samplerate; - } - *poutbuf = buf; - *poutbuf_size = buf_size; - return buf_size; - } - - fpc->avctx = avctx; - if (fpc->best_header_valid) - return get_best_header(fpc, poutbuf, poutbuf_size); - - /* If a best_header was found last call remove it with the buffer data. */ - if (fpc->best_header && fpc->best_header->best_child) { - FLACHeaderMarker *temp; - FLACHeaderMarker *best_child = fpc->best_header->best_child; - - /* Remove headers in list until the end of the best_header. */ - for (curr = fpc->headers; curr != best_child; curr = temp) { - if (curr != fpc->best_header) { - av_log(avctx, AV_LOG_DEBUG, - "dropping low score %i frame header from offset %i to %i\n", - curr->max_score, curr->offset, curr->next->offset); - } - temp = curr->next; - av_freep(&curr->link_penalty); - av_free(curr); - fpc->nb_headers_buffered--; - } - /* Release returned data from ring buffer. */ - av_fifo_drain(fpc->fifo_buf, best_child->offset); - - /* Fix the offset for the headers remaining to match the new buffer. */ - for (curr = best_child->next; curr; curr = curr->next) - curr->offset -= best_child->offset; - - fpc->nb_headers_buffered--; - best_child->offset = 0; - fpc->headers = best_child; - if (fpc->nb_headers_buffered >= FLAC_MIN_HEADERS) { - fpc->best_header = best_child; - return get_best_header(fpc, poutbuf, poutbuf_size); - } - fpc->best_header = NULL; - } else if (fpc->best_header) { - /* No end frame no need to delete the buffer; probably eof */ - FLACHeaderMarker *temp; - - for (curr = fpc->headers; curr != fpc->best_header; curr = temp) { - temp = curr->next; - av_freep(&curr->link_penalty); - av_free(curr); - } - fpc->headers = fpc->best_header->next; - av_freep(&fpc->best_header->link_penalty); - av_freep(&fpc->best_header); - } - - /* Find and score new headers. */ - /* buf_size is to zero when padding, so check for this since we do */ - /* not want to try to read more input once we have found the end. */ - /* Note that as (non-modified) parameters, buf can be non-NULL, */ - /* while buf_size is 0. */ - while ((buf && buf_size && read_end < buf + buf_size && - fpc->nb_headers_buffered < FLAC_MIN_HEADERS) - || ((!buf || !buf_size) && !fpc->end_padded)) { - int start_offset; - - /* Pad the end once if EOF, to check the final region for headers. */ - if (!buf || !buf_size) { - fpc->end_padded = 1; - buf_size = MAX_FRAME_HEADER_SIZE; - read_end = read_start + MAX_FRAME_HEADER_SIZE; - } else { - /* The maximum read size is the upper-bound of what the parser - needs to have the required number of frames buffered */ - int nb_desired = FLAC_MIN_HEADERS - fpc->nb_headers_buffered + 1; - read_end = read_end + FFMIN(buf + buf_size - read_end, - nb_desired * FLAC_AVG_FRAME_SIZE); - } - - /* Fill the buffer. */ - if ( av_fifo_space(fpc->fifo_buf) < read_end - read_start - && av_fifo_realloc2(fpc->fifo_buf, (read_end - read_start) + 2*av_fifo_size(fpc->fifo_buf)) < 0) { - av_log(avctx, AV_LOG_ERROR, - "couldn't reallocate buffer of size %td\n", - (read_end - read_start) + av_fifo_size(fpc->fifo_buf)); - goto handle_error; - } - - if (buf && buf_size) { - av_fifo_generic_write(fpc->fifo_buf, (void*) read_start, - read_end - read_start, NULL); - } else { - int8_t pad[MAX_FRAME_HEADER_SIZE] = { 0 }; - av_fifo_generic_write(fpc->fifo_buf, (void*) pad, sizeof(pad), NULL); - } - - /* Tag headers and update sequences. */ - start_offset = av_fifo_size(fpc->fifo_buf) - - ((read_end - read_start) + (MAX_FRAME_HEADER_SIZE - 1)); - start_offset = FFMAX(0, start_offset); - nb_headers = find_new_headers(fpc, start_offset); - - if (nb_headers < 0) { - av_log(avctx, AV_LOG_ERROR, - "find_new_headers couldn't allocate FLAC header\n"); - goto handle_error; - } - - fpc->nb_headers_buffered = nb_headers; - /* Wait till FLAC_MIN_HEADERS to output a valid frame. */ - if (!fpc->end_padded && fpc->nb_headers_buffered < FLAC_MIN_HEADERS) { - if (buf && read_end < buf + buf_size) { - read_start = read_end; - continue; - } else { - goto handle_error; - } - } - - /* If headers found, update the scores since we have longer chains. */ - if (fpc->end_padded || fpc->nb_headers_found) - score_sequences(fpc); - - /* restore the state pre-padding */ - if (fpc->end_padded) { - int warp = fpc->fifo_buf->wptr - fpc->fifo_buf->buffer < MAX_FRAME_HEADER_SIZE; - /* HACK: drain the tail of the fifo */ - fpc->fifo_buf->wptr -= MAX_FRAME_HEADER_SIZE; - fpc->fifo_buf->wndx -= MAX_FRAME_HEADER_SIZE; - if (warp) { - fpc->fifo_buf->wptr += fpc->fifo_buf->end - - fpc->fifo_buf->buffer; - } - buf_size = 0; - read_start = read_end = NULL; - } - } - - curr = fpc->headers; - for (curr = fpc->headers; curr; curr = curr->next) { - if (curr->max_score > 0 && - (!fpc->best_header || curr->max_score > fpc->best_header->max_score)) { - fpc->best_header = curr; - } - } - - if (fpc->best_header) { - fpc->best_header_valid = 1; - if (fpc->best_header->offset > 0) { - /* Output a junk frame. */ - av_log(avctx, AV_LOG_DEBUG, "Junk frame till offset %i\n", - fpc->best_header->offset); - - /* Set duration to 0. It is unknown or invalid in a junk frame. */ - s->duration = 0; - *poutbuf_size = fpc->best_header->offset; - *poutbuf = flac_fifo_read_wrap(fpc, 0, *poutbuf_size, - &fpc->wrap_buf, - &fpc->wrap_buf_allocated_size); - return buf_size ? (read_end - buf) : (fpc->best_header->offset - - av_fifo_size(fpc->fifo_buf)); - } - if (!buf_size) - return get_best_header(fpc, poutbuf, poutbuf_size); - } - -handle_error: - *poutbuf = NULL; - *poutbuf_size = 0; - return read_end - buf; -} - -static av_cold int flac_parse_init(AVCodecParserContext *c) -{ - FLACParseContext *fpc = c->priv_data; - fpc->pc = c; - /* There will generally be FLAC_MIN_HEADERS buffered in the fifo before - it drains. This is allocated early to avoid slow reallocation. */ - fpc->fifo_buf = av_fifo_alloc(FLAC_AVG_FRAME_SIZE * (FLAC_MIN_HEADERS + 3)); - if (!fpc->fifo_buf) - return AVERROR(ENOMEM); - return 0; -} - -static void flac_parse_close(AVCodecParserContext *c) -{ - FLACParseContext *fpc = c->priv_data; - FLACHeaderMarker *curr = fpc->headers, *temp; - - while (curr) { - temp = curr->next; - av_freep(&curr->link_penalty); - av_free(curr); - curr = temp; - } - av_fifo_free(fpc->fifo_buf); - av_free(fpc->wrap_buf); -} - -AVCodecParser ff_flac_parser = { - .codec_ids = { AV_CODEC_ID_FLAC }, - .priv_data_size = sizeof(FLACParseContext), - .parser_init = flac_parse_init, - .parser_parse = flac_parse, - .parser_close = flac_parse_close, -}; |