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-rw-r--r--media/ffvpx/libavcodec/flac_parser.c755
1 files changed, 755 insertions, 0 deletions
diff --git a/media/ffvpx/libavcodec/flac_parser.c b/media/ffvpx/libavcodec/flac_parser.c
new file mode 100644
index 000000000..f5cc35a4f
--- /dev/null
+++ b/media/ffvpx/libavcodec/flac_parser.c
@@ -0,0 +1,755 @@
+/*
+ * 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 4
+/** 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(**end_handle));
+ 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);
+ if (!(*end_handle)->link_penalty) {
+ av_freep(end_handle);
+ av_log(fpc->avctx, AV_LOG_ERROR,
+ "couldn't allocate link_penalty\n");
+ return AVERROR(ENOMEM);
+ }
+
+ 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);
+
+
+ if (fpc->pc->flags & PARSER_FLAG_USE_CODEC_TS){
+ if (header->fi.is_var_size)
+ fpc->pc->pts = header->fi.frame_or_sample_num;
+ else if (header->best_child)
+ fpc->pc->pts = header->fi.frame_or_sample_num * header->fi.blocksize;
+ }
+
+ 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;
+ if (fpc->pc->flags & PARSER_FLAG_USE_CODEC_TS){
+ fpc->pc->pts = fi.frame_or_sample_num;
+ if (!fi.is_var_size)
+ fpc->pc->pts *= fi.blocksize;
+ }
+ }
+ *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);
+ }
+
+ if (!av_fifo_space(fpc->fifo_buf) &&
+ av_fifo_size(fpc->fifo_buf) / FLAC_AVG_FRAME_SIZE >
+ fpc->nb_headers_buffered * 20) {
+ /* There is less than one valid flac header buffered for 20 headers
+ * buffered. Therefore the fifo is most likely filled with invalid
+ * data and the input is not a flac file. */
+ goto handle_error;
+ }
+
+ /* 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 %"PTRDIFF_SPECIFIER"\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;
+ }
+ }
+
+ 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 buf_size ? read_end - buf : 0;
+}
+
+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_array(FLAC_MIN_HEADERS + 3, FLAC_AVG_FRAME_SIZE);
+ if (!fpc->fifo_buf) {
+ av_log(fpc->avctx, AV_LOG_ERROR,
+ "couldn't allocate fifo_buf\n");
+ 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_freep(&fpc->fifo_buf);
+ av_freep(&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,
+};