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/* |
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* FLAC parser |
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* Copyright (c) 2010 Michael Chinen |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/** |
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* @file |
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* FLAC parser |
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* |
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* The FLAC parser buffers input until FLAC_MIN_HEADERS has been found. |
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* Each time it finds and verifies a CRC-8 header it sees which of the |
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* FLAC_MAX_SEQUENTIAL_HEADERS that came before it have a valid CRC-16 footer |
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* that ends at the newly found header. |
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* Headers are scored by FLAC_HEADER_BASE_SCORE plus the max of its crc-verified |
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* children, penalized by changes in sample rate, frame number, etc. |
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* The parser returns the frame with the highest score. |
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**/ |
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#include "libavutil/attributes.h" |
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#include "libavutil/crc.h" |
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#include "libavutil/fifo.h" |
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#include "bytestream.h" |
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#include "parser.h" |
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#include "flac.h" |
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/** maximum number of adjacent headers that compare CRCs against each other */ |
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#define FLAC_MAX_SEQUENTIAL_HEADERS 4 |
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/** minimum number of headers buffered and checked before returning frames */ |
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#define FLAC_MIN_HEADERS 10 |
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/** estimate for average size of a FLAC frame */ |
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#define FLAC_AVG_FRAME_SIZE 8192 |
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/** scoring settings for score_header */ |
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#define FLAC_HEADER_BASE_SCORE 10 |
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#define FLAC_HEADER_CHANGED_PENALTY 7 |
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#define FLAC_HEADER_CRC_FAIL_PENALTY 50 |
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#define FLAC_HEADER_NOT_PENALIZED_YET 100000 |
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#define FLAC_HEADER_NOT_SCORED_YET -100000 |
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/** largest possible size of flac header */ |
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#define MAX_FRAME_HEADER_SIZE 16 |
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typedef struct FLACHeaderMarker { |
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int offset; /**< byte offset from start of FLACParseContext->buffer */ |
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int link_penalty[FLAC_MAX_SEQUENTIAL_HEADERS]; /**< array of local scores |
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between this header and the one at a distance equal |
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array position */ |
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int max_score; /**< maximum score found after checking each child that |
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has a valid CRC */ |
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FLACFrameInfo fi; /**< decoded frame header info */ |
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struct FLACHeaderMarker *next; /**< next CRC-8 verified header that |
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immediately follows this one in |
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the bytestream */ |
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struct FLACHeaderMarker *best_child; /**< following frame header with |
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which this frame has the best |
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score with */ |
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} FLACHeaderMarker; |
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typedef struct FLACParseContext { |
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AVCodecParserContext *pc; /**< parent context */ |
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AVCodecContext *avctx; /**< codec context pointer for logging */ |
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FLACHeaderMarker *headers; /**< linked-list that starts at the first |
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CRC-8 verified header within buffer */ |
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FLACHeaderMarker *best_header; /**< highest scoring header within buffer */ |
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int nb_headers_found; /**< number of headers found in the last |
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flac_parse() call */ |
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int nb_headers_buffered; /**< number of headers that are buffered */ |
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int best_header_valid; /**< flag set when the parser returns junk; |
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if set return best_header next time */ |
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AVFifoBuffer *fifo_buf; /**< buffer to store all data until headers |
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can be verified */ |
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int end_padded; /**< specifies if fifo_buf's end is padded */ |
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uint8_t *wrap_buf; /**< general fifo read buffer when wrapped */ |
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int wrap_buf_allocated_size; /**< actual allocated size of the buffer */ |
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FLACFrameInfo last_fi; /**< last decoded frame header info */ |
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int last_fi_valid; /**< set if last_fi is valid */ |
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} FLACParseContext; |
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4714 |
static int frame_header_is_valid(AVCodecContext *avctx, const uint8_t *buf, |
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FLACFrameInfo *fi) |
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{ |
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GetBitContext gb; |
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4714 |
init_get_bits(&gb, buf, MAX_FRAME_HEADER_SIZE * 8); |
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4714 |
return !ff_flac_decode_frame_header(avctx, &gb, fi, 127); |
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} |
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/** |
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* Non-destructive fast fifo pointer fetching |
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* Returns a pointer from the specified offset. |
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* If possible the pointer points within the fifo buffer. |
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* Otherwise (if it would cause a wrap around,) a pointer to a user-specified |
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* buffer is used. |
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* The pointer can be NULL. In any case it will be reallocated to hold the size. |
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* If the returned pointer will be used after subsequent calls to flac_fifo_read_wrap |
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* then the subsequent calls should pass in a different wrap_buf so as to not |
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* overwrite the contents of the previous wrap_buf. |
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* This function is based on av_fifo_generic_read, which is why there is a comment |
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* about a memory barrier for SMP. |
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*/ |
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7309 |
static uint8_t *flac_fifo_read_wrap(FLACParseContext *fpc, int offset, int len, |
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uint8_t **wrap_buf, int *allocated_size) |
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{ |
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7309 |
AVFifoBuffer *f = fpc->fifo_buf; |
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uint8_t *start = f->rptr + offset; |
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uint8_t *tmp_buf; |
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✓✓ |
7309 |
if (start >= f->end) |
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1343 |
start -= f->end - f->buffer; |
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✓✓ |
7309 |
if (f->end - start >= len) |
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return start; |
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tmp_buf = av_fast_realloc(*wrap_buf, allocated_size, len); |
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✗✓ |
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if (!tmp_buf) { |
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av_log(fpc->avctx, AV_LOG_ERROR, |
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"couldn't reallocate wrap buffer of size %d", len); |
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return NULL; |
134 |
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} |
135 |
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*wrap_buf = tmp_buf; |
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do { |
137 |
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int seg_len = FFMIN(f->end - start, len); |
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memcpy(tmp_buf, start, seg_len); |
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tmp_buf = (uint8_t*)tmp_buf + seg_len; |
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// memory barrier needed for SMP here in theory |
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start += seg_len - (f->end - f->buffer); |
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len -= seg_len; |
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✓✓ |
246 |
} while (len > 0); |
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return *wrap_buf; |
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} |
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/** |
150 |
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* Return a pointer in the fifo buffer where the offset starts at until |
151 |
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* the wrap point or end of request. |
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* len will contain the valid length of the returned buffer. |
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* A second call to flac_fifo_read (with new offset and len) should be called |
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* to get the post-wrap buf if the returned len is less than the requested. |
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**/ |
156 |
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29651 |
static uint8_t *flac_fifo_read(FLACParseContext *fpc, int offset, int *len) |
157 |
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{ |
158 |
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29651 |
AVFifoBuffer *f = fpc->fifo_buf; |
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29651 |
uint8_t *start = f->rptr + offset; |
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✓✓ |
29651 |
if (start >= f->end) |
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13455 |
start -= f->end - f->buffer; |
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29651 |
*len = FFMIN(*len, f->end - start); |
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29651 |
return start; |
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} |
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4591 |
static int find_headers_search_validate(FLACParseContext *fpc, int offset) |
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{ |
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FLACFrameInfo fi; |
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uint8_t *header_buf; |
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4591 |
int size = 0; |
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4591 |
header_buf = flac_fifo_read_wrap(fpc, offset, |
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MAX_FRAME_HEADER_SIZE, |
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&fpc->wrap_buf, |
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&fpc->wrap_buf_allocated_size); |
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✓✓ |
4591 |
if (frame_header_is_valid(fpc->avctx, header_buf, &fi)) { |
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3837 |
FLACHeaderMarker **end_handle = &fpc->headers; |
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int i; |
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size = 0; |
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✓✓ |
31259 |
while (*end_handle) { |
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27422 |
end_handle = &(*end_handle)->next; |
183 |
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27422 |
size++; |
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} |
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3837 |
*end_handle = av_mallocz(sizeof(**end_handle)); |
187 |
✗✓ |
3837 |
if (!*end_handle) { |
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av_log(fpc->avctx, AV_LOG_ERROR, |
189 |
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"couldn't allocate FLACHeaderMarker\n"); |
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return AVERROR(ENOMEM); |
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} |
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3837 |
(*end_handle)->fi = fi; |
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(*end_handle)->offset = offset; |
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195 |
✓✓ |
19185 |
for (i = 0; i < FLAC_MAX_SEQUENTIAL_HEADERS; i++) |
196 |
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15348 |
(*end_handle)->link_penalty[i] = FLAC_HEADER_NOT_PENALIZED_YET; |
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198 |
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3837 |
fpc->nb_headers_found++; |
199 |
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3837 |
size++; |
200 |
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} |
201 |
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4591 |
return size; |
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} |
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204 |
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29651 |
static int find_headers_search(FLACParseContext *fpc, uint8_t *buf, |
205 |
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int buf_size, int search_start) |
206 |
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{ |
207 |
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29651 |
int size = 0, mod_offset = (buf_size - 1) % 4, i, j; |
208 |
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uint32_t x; |
209 |
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210 |
✓✓ |
30301 |
for (i = 0; i < mod_offset; i++) { |
211 |
✓✓ |
650 |
if ((AV_RB16(buf + i) & 0xFFFE) == 0xFFF8) { |
212 |
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61 |
int ret = find_headers_search_validate(fpc, search_start + i); |
213 |
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61 |
size = FFMAX(size, ret); |
214 |
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} |
215 |
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} |
216 |
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217 |
✓✓ |
7566714 |
for (; i < buf_size - 1; i += 4) { |
218 |
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7537063 |
x = AV_RN32(buf + i); |
219 |
✓✓ |
7537063 |
if (((x & ~(x + 0x01010101)) & 0x80808080)) { |
220 |
✓✓ |
525425 |
for (j = 0; j < 4; j++) { |
221 |
✓✓ |
420340 |
if ((AV_RB16(buf + i + j) & 0xFFFE) == 0xFFF8) { |
222 |
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4530 |
int ret = find_headers_search_validate(fpc, search_start + i + j); |
223 |
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4530 |
size = FFMAX(size, ret); |
224 |
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} |
225 |
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} |
226 |
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} |
227 |
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} |
228 |
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29651 |
return size; |
229 |
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} |
230 |
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231 |
|
29513 |
static int find_new_headers(FLACParseContext *fpc, int search_start) |
232 |
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{ |
233 |
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FLACHeaderMarker *end; |
234 |
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29513 |
int search_end, size = 0, read_len, temp; |
235 |
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uint8_t *buf; |
236 |
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29513 |
fpc->nb_headers_found = 0; |
237 |
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238 |
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/* Search for a new header of at most 16 bytes. */ |
239 |
|
29513 |
search_end = av_fifo_size(fpc->fifo_buf) - (MAX_FRAME_HEADER_SIZE - 1); |
240 |
|
29513 |
read_len = search_end - search_start + 1; |
241 |
|
29513 |
buf = flac_fifo_read(fpc, search_start, &read_len); |
242 |
|
29513 |
size = find_headers_search(fpc, buf, read_len, search_start); |
243 |
|
29513 |
search_start += read_len - 1; |
244 |
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|
245 |
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/* If fifo end was hit do the wrap around. */ |
246 |
✓✓ |
29513 |
if (search_start != search_end) { |
247 |
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uint8_t wrap[2]; |
248 |
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|
249 |
|
138 |
wrap[0] = buf[read_len - 1]; |
250 |
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/* search_start + 1 is the post-wrap offset in the fifo. */ |
251 |
|
138 |
read_len = search_end - (search_start + 1) + 1; |
252 |
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253 |
|
138 |
buf = flac_fifo_read(fpc, search_start + 1, &read_len); |
254 |
|
138 |
wrap[1] = buf[0]; |
255 |
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|
256 |
✗✓ |
138 |
if ((AV_RB16(wrap) & 0xFFFE) == 0xFFF8) { |
257 |
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temp = find_headers_search_validate(fpc, search_start); |
258 |
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size = FFMAX(size, temp); |
259 |
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} |
260 |
|
138 |
search_start++; |
261 |
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262 |
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/* Continue to do the last half of the wrap. */ |
263 |
|
138 |
temp = find_headers_search(fpc, buf, read_len, search_start); |
264 |
|
138 |
size = FFMAX(size, temp); |
265 |
|
138 |
search_start += read_len - 1; |
266 |
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} |
267 |
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|
268 |
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/* Return the size even if no new headers were found. */ |
269 |
✓✓✓✓
|
29513 |
if (!size && fpc->headers) |
270 |
✓✓ |
251374 |
for (end = fpc->headers; end; end = end->next) |
271 |
|
225404 |
size++; |
272 |
|
29513 |
return size; |
273 |
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} |
274 |
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275 |
|
38696 |
static int check_header_fi_mismatch(FLACParseContext *fpc, |
276 |
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FLACFrameInfo *header_fi, |
277 |
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FLACFrameInfo *child_fi, |
278 |
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int log_level_offset) |
279 |
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{ |
280 |
|
38696 |
int deduction = 0; |
281 |
✗✓ |
38696 |
if (child_fi->samplerate != header_fi->samplerate) { |
282 |
|
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deduction += FLAC_HEADER_CHANGED_PENALTY; |
283 |
|
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av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset, |
284 |
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"sample rate change detected in adjacent frames\n"); |
285 |
|
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} |
286 |
✗✓ |
38696 |
if (child_fi->bps != header_fi->bps) { |
287 |
|
|
deduction += FLAC_HEADER_CHANGED_PENALTY; |
288 |
|
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av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset, |
289 |
|
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"bits per sample change detected in adjacent frames\n"); |
290 |
|
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} |
291 |
✗✓ |
38696 |
if (child_fi->is_var_size != header_fi->is_var_size) { |
292 |
|
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/* Changing blocking strategy not allowed per the spec */ |
293 |
|
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deduction += FLAC_HEADER_BASE_SCORE; |
294 |
|
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av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset, |
295 |
|
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"blocking strategy change detected in adjacent frames\n"); |
296 |
|
|
} |
297 |
✗✓ |
38696 |
if (child_fi->channels != header_fi->channels) { |
298 |
|
|
deduction += FLAC_HEADER_CHANGED_PENALTY; |
299 |
|
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av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset, |
300 |
|
|
"number of channels change detected in adjacent frames\n"); |
301 |
|
|
} |
302 |
|
38696 |
return deduction; |
303 |
|
|
} |
304 |
|
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|
305 |
|
16309 |
static int check_header_mismatch(FLACParseContext *fpc, |
306 |
|
|
FLACHeaderMarker *header, |
307 |
|
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FLACHeaderMarker *child, |
308 |
|
|
int log_level_offset) |
309 |
|
|
{ |
310 |
|
16309 |
FLACFrameInfo *header_fi = &header->fi, *child_fi = &child->fi; |
311 |
|
16309 |
int deduction, deduction_expected = 0, i; |
312 |
|
16309 |
deduction = check_header_fi_mismatch(fpc, header_fi, child_fi, |
313 |
|
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log_level_offset); |
314 |
|
|
/* Check sample and frame numbers. */ |
315 |
|
16309 |
if ((child_fi->frame_or_sample_num - header_fi->frame_or_sample_num |
316 |
✓✗ |
16309 |
!= header_fi->blocksize) && |
317 |
|
16309 |
(child_fi->frame_or_sample_num |
318 |
✓✓ |
16309 |
!= header_fi->frame_or_sample_num + 1)) { |
319 |
|
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FLACHeaderMarker *curr; |
320 |
|
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int64_t expected_frame_num, expected_sample_num; |
321 |
|
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/* If there are frames in the middle we expect this deduction, |
322 |
|
|
as they are probably valid and this one follows it */ |
323 |
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|
324 |
|
10059 |
expected_frame_num = expected_sample_num = header_fi->frame_or_sample_num; |
325 |
|
10059 |
curr = header; |
326 |
✓✓ |
39924 |
while (curr != child) { |
327 |
|
|
/* Ignore frames that failed all crc checks */ |
328 |
✓✗ |
29865 |
for (i = 0; i < FLAC_MAX_SEQUENTIAL_HEADERS; i++) { |
329 |
✓✗ |
29865 |
if (curr->link_penalty[i] < FLAC_HEADER_CRC_FAIL_PENALTY) { |
330 |
|
29865 |
expected_frame_num++; |
331 |
|
29865 |
expected_sample_num += curr->fi.blocksize; |
332 |
|
29865 |
break; |
333 |
|
|
} |
334 |
|
|
} |
335 |
|
29865 |
curr = curr->next; |
336 |
|
|
} |
337 |
|
|
|
338 |
✗✓ |
10059 |
if (expected_frame_num == child_fi->frame_or_sample_num || |
339 |
|
|
expected_sample_num == child_fi->frame_or_sample_num) |
340 |
|
10059 |
deduction_expected = deduction ? 0 : 1; |
341 |
|
|
|
342 |
|
10059 |
deduction += FLAC_HEADER_CHANGED_PENALTY; |
343 |
|
10059 |
av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset, |
344 |
|
|
"sample/frame number mismatch in adjacent frames\n"); |
345 |
|
|
} |
346 |
|
|
|
347 |
|
|
/* If we have suspicious headers, check the CRC between them */ |
348 |
✓✓✗✓
|
16309 |
if (deduction && !deduction_expected) { |
349 |
|
|
FLACHeaderMarker *curr; |
350 |
|
|
int read_len; |
351 |
|
|
uint8_t *buf; |
352 |
|
|
uint32_t crc = 1; |
353 |
|
|
int inverted_test = 0; |
354 |
|
|
|
355 |
|
|
/* Since CRC is expensive only do it if we haven't yet. |
356 |
|
|
This assumes a CRC penalty is greater than all other check penalties */ |
357 |
|
|
curr = header->next; |
358 |
|
|
for (i = 0; i < FLAC_MAX_SEQUENTIAL_HEADERS && curr != child; i++) |
359 |
|
|
curr = curr->next; |
360 |
|
|
|
361 |
|
|
if (header->link_penalty[i] < FLAC_HEADER_CRC_FAIL_PENALTY || |
362 |
|
|
header->link_penalty[i] == FLAC_HEADER_NOT_PENALIZED_YET) { |
363 |
|
|
FLACHeaderMarker *start, *end; |
364 |
|
|
|
365 |
|
|
/* Although overlapping chains are scored, the crc should never |
366 |
|
|
have to be computed twice for a single byte. */ |
367 |
|
|
start = header; |
368 |
|
|
end = child; |
369 |
|
|
if (i > 0 && |
370 |
|
|
header->link_penalty[i - 1] >= FLAC_HEADER_CRC_FAIL_PENALTY) { |
371 |
|
|
while (start->next != child) |
372 |
|
|
start = start->next; |
373 |
|
|
inverted_test = 1; |
374 |
|
|
} else if (i > 0 && |
375 |
|
|
header->next->link_penalty[i-1] >= |
376 |
|
|
FLAC_HEADER_CRC_FAIL_PENALTY ) { |
377 |
|
|
end = header->next; |
378 |
|
|
inverted_test = 1; |
379 |
|
|
} |
380 |
|
|
|
381 |
|
|
read_len = end->offset - start->offset; |
382 |
|
|
buf = flac_fifo_read(fpc, start->offset, &read_len); |
383 |
|
|
crc = av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, buf, read_len); |
384 |
|
|
read_len = (end->offset - start->offset) - read_len; |
385 |
|
|
|
386 |
|
|
if (read_len) { |
387 |
|
|
buf = flac_fifo_read(fpc, end->offset - read_len, &read_len); |
388 |
|
|
crc = av_crc(av_crc_get_table(AV_CRC_16_ANSI), crc, buf, read_len); |
389 |
|
|
} |
390 |
|
|
} |
391 |
|
|
|
392 |
|
|
if (!crc ^ !inverted_test) { |
393 |
|
|
deduction += FLAC_HEADER_CRC_FAIL_PENALTY; |
394 |
|
|
av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset, |
395 |
|
|
"crc check failed from offset %i (frame %"PRId64") to %i (frame %"PRId64")\n", |
396 |
|
|
header->offset, header_fi->frame_or_sample_num, |
397 |
|
|
child->offset, child_fi->frame_or_sample_num); |
398 |
|
|
} |
399 |
|
|
} |
400 |
|
16309 |
return deduction; |
401 |
|
|
} |
402 |
|
|
|
403 |
|
|
/** |
404 |
|
|
* Score a header. |
405 |
|
|
* |
406 |
|
|
* Give FLAC_HEADER_BASE_SCORE points to a frame for existing. |
407 |
|
|
* If it has children, (subsequent frames of which the preceding CRC footer |
408 |
|
|
* validates against this one,) then take the maximum score of the children, |
409 |
|
|
* with a penalty of FLAC_HEADER_CHANGED_PENALTY applied for each change to |
410 |
|
|
* bps, sample rate, channels, but not decorrelation mode, or blocksize, |
411 |
|
|
* because it can change often. |
412 |
|
|
**/ |
413 |
|
95861 |
static int score_header(FLACParseContext *fpc, FLACHeaderMarker *header) |
414 |
|
|
{ |
415 |
|
|
FLACHeaderMarker *child; |
416 |
|
95861 |
int dist = 0; |
417 |
|
|
int child_score; |
418 |
|
95861 |
int base_score = FLAC_HEADER_BASE_SCORE; |
419 |
✓✓ |
95861 |
if (header->max_score != FLAC_HEADER_NOT_SCORED_YET) |
420 |
|
71891 |
return header->max_score; |
421 |
|
|
|
422 |
|
|
/* Modify the base score with changes from the last output header */ |
423 |
✓✓ |
23970 |
if (fpc->last_fi_valid) { |
424 |
|
|
/* Silence the log since this will be repeated if selected */ |
425 |
|
22387 |
base_score -= check_header_fi_mismatch(fpc, &fpc->last_fi, &header->fi, |
426 |
|
|
AV_LOG_DEBUG); |
427 |
|
|
} |
428 |
|
|
|
429 |
|
23970 |
header->max_score = base_score; |
430 |
|
|
|
431 |
|
|
/* Check and compute the children's scores. */ |
432 |
|
23970 |
child = header->next; |
433 |
✓✓✓✓
|
95861 |
for (dist = 0; dist < FLAC_MAX_SEQUENTIAL_HEADERS && child; dist++) { |
434 |
|
|
/* Look at the child's frame header info and penalize suspicious |
435 |
|
|
changes between the headers. */ |
436 |
✓✓ |
71891 |
if (header->link_penalty[dist] == FLAC_HEADER_NOT_PENALIZED_YET) { |
437 |
|
13729 |
header->link_penalty[dist] = check_header_mismatch(fpc, header, |
438 |
|
|
child, AV_LOG_DEBUG); |
439 |
|
|
} |
440 |
|
71891 |
child_score = score_header(fpc, child) - header->link_penalty[dist]; |
441 |
|
|
|
442 |
✓✓ |
71891 |
if (FLAC_HEADER_BASE_SCORE + child_score > header->max_score) { |
443 |
|
|
/* Keep the child because the frame scoring is dynamic. */ |
444 |
|
21566 |
header->best_child = child; |
445 |
|
21566 |
header->max_score = base_score + child_score; |
446 |
|
|
} |
447 |
|
71891 |
child = child->next; |
448 |
|
|
} |
449 |
|
|
|
450 |
|
23970 |
return header->max_score; |
451 |
|
|
} |
452 |
|
|
|
453 |
|
2404 |
static void score_sequences(FLACParseContext *fpc) |
454 |
|
|
{ |
455 |
|
|
FLACHeaderMarker *curr; |
456 |
|
2404 |
int best_score = 0;//FLAC_HEADER_NOT_SCORED_YET; |
457 |
|
|
/* First pass to clear all old scores. */ |
458 |
✓✓ |
26374 |
for (curr = fpc->headers; curr; curr = curr->next) |
459 |
|
23970 |
curr->max_score = FLAC_HEADER_NOT_SCORED_YET; |
460 |
|
|
|
461 |
|
|
/* Do a second pass to score them all. */ |
462 |
✓✓ |
26374 |
for (curr = fpc->headers; curr; curr = curr->next) { |
463 |
✓✓ |
23970 |
if (score_header(fpc, curr) > best_score) { |
464 |
|
2404 |
fpc->best_header = curr; |
465 |
|
2404 |
best_score = curr->max_score; |
466 |
|
|
} |
467 |
|
|
} |
468 |
|
2404 |
} |
469 |
|
|
|
470 |
|
2612 |
static int get_best_header(FLACParseContext *fpc, const uint8_t **poutbuf, |
471 |
|
|
int *poutbuf_size) |
472 |
|
|
{ |
473 |
|
2612 |
FLACHeaderMarker *header = fpc->best_header; |
474 |
|
2612 |
FLACHeaderMarker *child = header->best_child; |
475 |
✓✓ |
2612 |
if (!child) { |
476 |
|
32 |
*poutbuf_size = av_fifo_size(fpc->fifo_buf) - header->offset; |
477 |
|
|
} else { |
478 |
|
2580 |
*poutbuf_size = child->offset - header->offset; |
479 |
|
|
|
480 |
|
|
/* If the child has suspicious changes, log them */ |
481 |
|
2580 |
check_header_mismatch(fpc, header, child, 0); |
482 |
|
|
} |
483 |
|
|
|
484 |
✓✗ |
2612 |
if (header->fi.channels != fpc->avctx->channels || |
485 |
✗✓ |
2612 |
!fpc->avctx->channel_layout) { |
486 |
|
|
fpc->avctx->channels = header->fi.channels; |
487 |
|
|
ff_flac_set_channel_layout(fpc->avctx); |
488 |
|
|
} |
489 |
|
2612 |
fpc->avctx->sample_rate = header->fi.samplerate; |
490 |
|
2612 |
fpc->pc->duration = header->fi.blocksize; |
491 |
|
2612 |
*poutbuf = flac_fifo_read_wrap(fpc, header->offset, *poutbuf_size, |
492 |
|
|
&fpc->wrap_buf, |
493 |
|
|
&fpc->wrap_buf_allocated_size); |
494 |
|
|
|
495 |
|
|
|
496 |
✓✗ |
2612 |
if (fpc->pc->flags & PARSER_FLAG_USE_CODEC_TS) { |
497 |
✗✓ |
2612 |
if (header->fi.is_var_size) |
498 |
|
|
fpc->pc->pts = header->fi.frame_or_sample_num; |
499 |
✓✓ |
2612 |
else if (header->best_child) |
500 |
|
2580 |
fpc->pc->pts = header->fi.frame_or_sample_num * header->fi.blocksize; |
501 |
|
|
} |
502 |
|
|
|
503 |
|
2612 |
fpc->best_header_valid = 0; |
504 |
|
2612 |
fpc->last_fi_valid = 1; |
505 |
|
2612 |
fpc->last_fi = header->fi; |
506 |
|
|
|
507 |
|
|
/* Return the negative overread index so the client can compute pos. |
508 |
|
|
This should be the amount overread to the beginning of the child */ |
509 |
✓✓ |
2612 |
if (child) |
510 |
|
2580 |
return child->offset - av_fifo_size(fpc->fifo_buf); |
511 |
|
32 |
return 0; |
512 |
|
|
} |
513 |
|
|
|
514 |
|
32254 |
static int flac_parse(AVCodecParserContext *s, AVCodecContext *avctx, |
515 |
|
|
const uint8_t **poutbuf, int *poutbuf_size, |
516 |
|
|
const uint8_t *buf, int buf_size) |
517 |
|
|
{ |
518 |
|
32254 |
FLACParseContext *fpc = s->priv_data; |
519 |
|
|
FLACHeaderMarker *curr; |
520 |
|
|
int nb_headers; |
521 |
|
32254 |
const uint8_t *read_end = buf; |
522 |
|
32254 |
const uint8_t *read_start = buf; |
523 |
|
|
|
524 |
✓✓ |
32254 |
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { |
525 |
|
|
FLACFrameInfo fi; |
526 |
✓✓ |
123 |
if (frame_header_is_valid(avctx, buf, &fi)) { |
527 |
|
115 |
s->duration = fi.blocksize; |
528 |
✗✓ |
115 |
if (!avctx->sample_rate) |
529 |
|
|
avctx->sample_rate = fi.samplerate; |
530 |
✗✓ |
115 |
if (fpc->pc->flags & PARSER_FLAG_USE_CODEC_TS) { |
531 |
|
|
fpc->pc->pts = fi.frame_or_sample_num; |
532 |
|
|
if (!fi.is_var_size) |
533 |
|
|
fpc->pc->pts *= fi.blocksize; |
534 |
|
|
} |
535 |
|
|
} |
536 |
|
123 |
*poutbuf = buf; |
537 |
|
123 |
*poutbuf_size = buf_size; |
538 |
|
123 |
return buf_size; |
539 |
|
|
} |
540 |
|
|
|
541 |
|
32131 |
fpc->avctx = avctx; |
542 |
✓✓ |
32131 |
if (fpc->best_header_valid) |
543 |
|
2363 |
return get_best_header(fpc, poutbuf, poutbuf_size); |
544 |
|
|
|
545 |
|
|
/* If a best_header was found last call remove it with the buffer data. */ |
546 |
✓✓✓✓
|
29768 |
if (fpc->best_header && fpc->best_header->best_child) { |
547 |
|
|
FLACHeaderMarker *temp; |
548 |
|
2472 |
FLACHeaderMarker *best_child = fpc->best_header->best_child; |
549 |
|
|
|
550 |
|
|
/* Remove headers in list until the end of the best_header. */ |
551 |
✓✓ |
4944 |
for (curr = fpc->headers; curr != best_child; curr = temp) { |
552 |
✗✓ |
2472 |
if (curr != fpc->best_header) { |
553 |
|
|
av_log(avctx, AV_LOG_DEBUG, |
554 |
|
|
"dropping low score %i frame header from offset %i to %i\n", |
555 |
|
|
curr->max_score, curr->offset, curr->next->offset); |
556 |
|
|
} |
557 |
|
2472 |
temp = curr->next; |
558 |
|
2472 |
av_free(curr); |
559 |
|
2472 |
fpc->nb_headers_buffered--; |
560 |
|
|
} |
561 |
|
|
/* Release returned data from ring buffer. */ |
562 |
|
2472 |
av_fifo_drain(fpc->fifo_buf, best_child->offset); |
563 |
|
|
|
564 |
|
|
/* Fix the offset for the headers remaining to match the new buffer. */ |
565 |
✓✓ |
21397 |
for (curr = best_child->next; curr; curr = curr->next) |
566 |
|
18925 |
curr->offset -= best_child->offset; |
567 |
|
|
|
568 |
|
2472 |
best_child->offset = 0; |
569 |
|
2472 |
fpc->headers = best_child; |
570 |
✓✓ |
2472 |
if (fpc->nb_headers_buffered >= FLAC_MIN_HEADERS) { |
571 |
|
29 |
fpc->best_header = best_child; |
572 |
|
29 |
return get_best_header(fpc, poutbuf, poutbuf_size); |
573 |
|
|
} |
574 |
|
2443 |
fpc->best_header = NULL; |
575 |
✓✓ |
27296 |
} else if (fpc->best_header) { |
576 |
|
|
/* No end frame no need to delete the buffer; probably eof */ |
577 |
|
|
FLACHeaderMarker *temp; |
578 |
|
|
|
579 |
✗✓ |
32 |
for (curr = fpc->headers; curr != fpc->best_header; curr = temp) { |
580 |
|
|
temp = curr->next; |
581 |
|
|
av_free(curr); |
582 |
|
|
fpc->nb_headers_buffered--; |
583 |
|
|
} |
584 |
|
32 |
fpc->headers = fpc->best_header->next; |
585 |
|
32 |
av_freep(&fpc->best_header); |
586 |
|
32 |
fpc->nb_headers_buffered--; |
587 |
|
|
} |
588 |
|
|
|
589 |
|
|
/* Find and score new headers. */ |
590 |
|
|
/* buf_size is zero when flushing, so check for this since we do */ |
591 |
|
|
/* not want to try to read more input once we have found the end. */ |
592 |
|
|
/* Also note that buf can't be NULL. */ |
593 |
✓✓✓✓
|
32143 |
while ((buf_size && read_end < buf + buf_size && |
594 |
✓✗ |
29478 |
fpc->nb_headers_buffered < FLAC_MIN_HEADERS) |
595 |
✓✓✓✓
|
2665 |
|| (!buf_size && !fpc->end_padded)) { |
596 |
|
|
int start_offset; |
597 |
|
|
|
598 |
|
|
/* Pad the end once if EOF, to check the final region for headers. */ |
599 |
✓✓ |
29513 |
if (!buf_size) { |
600 |
|
35 |
fpc->end_padded = 1; |
601 |
|
35 |
read_end = read_start + MAX_FRAME_HEADER_SIZE; |
602 |
|
|
} else { |
603 |
|
|
/* The maximum read size is the upper-bound of what the parser |
604 |
|
|
needs to have the required number of frames buffered */ |
605 |
|
29478 |
int nb_desired = FLAC_MIN_HEADERS - fpc->nb_headers_buffered + 1; |
606 |
✗✓ |
29478 |
read_end = read_end + FFMIN(buf + buf_size - read_end, |
607 |
|
|
nb_desired * FLAC_AVG_FRAME_SIZE); |
608 |
|
|
} |
609 |
|
|
|
610 |
✗✓ |
29513 |
if (!av_fifo_space(fpc->fifo_buf) && |
611 |
|
|
av_fifo_size(fpc->fifo_buf) / FLAC_AVG_FRAME_SIZE > |
612 |
|
|
fpc->nb_headers_buffered * 20) { |
613 |
|
|
/* There is less than one valid flac header buffered for 20 headers |
614 |
|
|
* buffered. Therefore the fifo is most likely filled with invalid |
615 |
|
|
* data and the input is not a flac file. */ |
616 |
|
|
goto handle_error; |
617 |
|
|
} |
618 |
|
|
|
619 |
|
|
/* Fill the buffer. */ |
620 |
✓✓ |
29513 |
if ( av_fifo_space(fpc->fifo_buf) < read_end - read_start |
621 |
✗✓ |
23 |
&& av_fifo_realloc2(fpc->fifo_buf, (read_end - read_start) + 2*av_fifo_size(fpc->fifo_buf)) < 0) { |
622 |
|
|
av_log(avctx, AV_LOG_ERROR, |
623 |
|
|
"couldn't reallocate buffer of size %"PTRDIFF_SPECIFIER"\n", |
624 |
|
|
(read_end - read_start) + av_fifo_size(fpc->fifo_buf)); |
625 |
|
|
goto handle_error; |
626 |
|
|
} |
627 |
|
|
|
628 |
✓✓ |
29513 |
if (buf_size) { |
629 |
|
29478 |
av_fifo_generic_write(fpc->fifo_buf, (void*) read_start, |
630 |
|
29478 |
read_end - read_start, NULL); |
631 |
|
|
} else { |
632 |
|
35 |
int8_t pad[MAX_FRAME_HEADER_SIZE] = { 0 }; |
633 |
|
35 |
av_fifo_generic_write(fpc->fifo_buf, pad, sizeof(pad), NULL); |
634 |
|
|
} |
635 |
|
|
|
636 |
|
|
/* Tag headers and update sequences. */ |
637 |
|
29513 |
start_offset = av_fifo_size(fpc->fifo_buf) - |
638 |
|
29513 |
((read_end - read_start) + (MAX_FRAME_HEADER_SIZE - 1)); |
639 |
|
29513 |
start_offset = FFMAX(0, start_offset); |
640 |
|
29513 |
nb_headers = find_new_headers(fpc, start_offset); |
641 |
|
|
|
642 |
✗✓ |
29513 |
if (nb_headers < 0) { |
643 |
|
|
av_log(avctx, AV_LOG_ERROR, |
644 |
|
|
"find_new_headers couldn't allocate FLAC header\n"); |
645 |
|
|
goto handle_error; |
646 |
|
|
} |
647 |
|
|
|
648 |
|
29513 |
fpc->nb_headers_buffered = nb_headers; |
649 |
|
|
/* Wait till FLAC_MIN_HEADERS to output a valid frame. */ |
650 |
✓✓✓✓
|
29513 |
if (!fpc->end_padded && fpc->nb_headers_buffered < FLAC_MIN_HEADERS) { |
651 |
✗✓ |
27109 |
if (read_end < buf + buf_size) { |
652 |
|
|
read_start = read_end; |
653 |
|
|
continue; |
654 |
|
|
} else { |
655 |
|
27109 |
goto handle_error; |
656 |
|
|
} |
657 |
|
|
} |
658 |
|
|
|
659 |
|
|
/* If headers found, update the scores since we have longer chains. */ |
660 |
✓✓✓✗
|
2404 |
if (fpc->end_padded || fpc->nb_headers_found) |
661 |
|
2404 |
score_sequences(fpc); |
662 |
|
|
|
663 |
|
|
/* restore the state pre-padding */ |
664 |
✓✓ |
2404 |
if (fpc->end_padded) { |
665 |
|
35 |
int warp = fpc->fifo_buf->wptr - fpc->fifo_buf->buffer < MAX_FRAME_HEADER_SIZE; |
666 |
|
|
/* HACK: drain the tail of the fifo */ |
667 |
|
35 |
fpc->fifo_buf->wptr -= MAX_FRAME_HEADER_SIZE; |
668 |
|
35 |
fpc->fifo_buf->wndx -= MAX_FRAME_HEADER_SIZE; |
669 |
✗✓ |
35 |
if (warp) { |
670 |
|
|
fpc->fifo_buf->wptr += fpc->fifo_buf->end - |
671 |
|
|
fpc->fifo_buf->buffer; |
672 |
|
|
} |
673 |
|
35 |
read_start = read_end = NULL; |
674 |
|
|
} |
675 |
|
|
} |
676 |
|
|
|
677 |
✓✓ |
27466 |
for (curr = fpc->headers; curr; curr = curr->next) { |
678 |
✓✓✗✓
|
24836 |
if (!fpc->best_header || curr->max_score > fpc->best_header->max_score) { |
679 |
|
194 |
fpc->best_header = curr; |
680 |
|
|
} |
681 |
|
|
} |
682 |
|
|
|
683 |
✓✓✗✓
|
2630 |
if (fpc->best_header && fpc->best_header->max_score <= 0) { |
684 |
|
|
// Only accept a bad header if there is no other option to continue |
685 |
|
|
if (!buf_size || read_end != buf || fpc->nb_headers_buffered < FLAC_MIN_HEADERS) |
686 |
|
|
fpc->best_header = NULL; |
687 |
|
|
} |
688 |
|
|
|
689 |
✓✓ |
2630 |
if (fpc->best_header) { |
690 |
|
2598 |
fpc->best_header_valid = 1; |
691 |
✓✓ |
2598 |
if (fpc->best_header->offset > 0) { |
692 |
|
|
/* Output a junk frame. */ |
693 |
|
106 |
av_log(avctx, AV_LOG_DEBUG, "Junk frame till offset %i\n", |
694 |
|
106 |
fpc->best_header->offset); |
695 |
|
|
|
696 |
|
|
/* Set duration to 0. It is unknown or invalid in a junk frame. */ |
697 |
|
106 |
s->duration = 0; |
698 |
|
106 |
*poutbuf_size = fpc->best_header->offset; |
699 |
|
106 |
*poutbuf = flac_fifo_read_wrap(fpc, 0, *poutbuf_size, |
700 |
|
|
&fpc->wrap_buf, |
701 |
|
|
&fpc->wrap_buf_allocated_size); |
702 |
✓✓ |
115 |
return buf_size ? (read_end - buf) : (fpc->best_header->offset - |
703 |
|
9 |
av_fifo_size(fpc->fifo_buf)); |
704 |
|
|
} |
705 |
✓✓ |
2492 |
if (!buf_size) |
706 |
|
220 |
return get_best_header(fpc, poutbuf, poutbuf_size); |
707 |
|
|
} |
708 |
|
|
|
709 |
|
2304 |
handle_error: |
710 |
|
29413 |
*poutbuf = NULL; |
711 |
|
29413 |
*poutbuf_size = 0; |
712 |
✓✓ |
29413 |
return buf_size ? read_end - buf : 0; |
713 |
|
|
} |
714 |
|
|
|
715 |
|
202 |
static av_cold int flac_parse_init(AVCodecParserContext *c) |
716 |
|
|
{ |
717 |
|
202 |
FLACParseContext *fpc = c->priv_data; |
718 |
|
202 |
fpc->pc = c; |
719 |
|
|
/* There will generally be FLAC_MIN_HEADERS buffered in the fifo before |
720 |
|
|
it drains. This is allocated early to avoid slow reallocation. */ |
721 |
|
202 |
fpc->fifo_buf = av_fifo_alloc_array(FLAC_MIN_HEADERS + 3, FLAC_AVG_FRAME_SIZE); |
722 |
✗✓ |
202 |
if (!fpc->fifo_buf) { |
723 |
|
|
av_log(fpc->avctx, AV_LOG_ERROR, |
724 |
|
|
"couldn't allocate fifo_buf\n"); |
725 |
|
|
return AVERROR(ENOMEM); |
726 |
|
|
} |
727 |
|
202 |
return 0; |
728 |
|
|
} |
729 |
|
|
|
730 |
|
202 |
static void flac_parse_close(AVCodecParserContext *c) |
731 |
|
|
{ |
732 |
|
202 |
FLACParseContext *fpc = c->priv_data; |
733 |
|
202 |
FLACHeaderMarker *curr = fpc->headers, *temp; |
734 |
|
|
|
735 |
✓✓ |
1535 |
while (curr) { |
736 |
|
1333 |
temp = curr->next; |
737 |
|
1333 |
av_free(curr); |
738 |
|
1333 |
curr = temp; |
739 |
|
|
} |
740 |
|
202 |
fpc->headers = NULL; |
741 |
|
202 |
av_fifo_freep(&fpc->fifo_buf); |
742 |
|
202 |
av_freep(&fpc->wrap_buf); |
743 |
|
202 |
} |
744 |
|
|
|
745 |
|
|
AVCodecParser ff_flac_parser = { |
746 |
|
|
.codec_ids = { AV_CODEC_ID_FLAC }, |
747 |
|
|
.priv_data_size = sizeof(FLACParseContext), |
748 |
|
|
.parser_init = flac_parse_init, |
749 |
|
|
.parser_parse = flac_parse, |
750 |
|
|
.parser_close = flac_parse_close, |
751 |
|
|
}; |