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@@ -0,0 +1,648 @@
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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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+/**
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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 it's 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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+
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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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+
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+/** maximum number of adjacent headers that compare CRCs against each other */
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+#define FLAC_MAX_SEQUENTIAL_HEADERS 3
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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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+
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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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+
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+/** largest possible size of flac header */
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+#define MAX_FRAME_HEADER_SIZE 16
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+
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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; /**< pointer to array of local scores between this header
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+ and the one at a distance equal 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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+
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+typedef struct FLACParseContext {
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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 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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+} FLACParseContext;
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+
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+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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+ init_get_bits(&gb, buf, MAX_FRAME_HEADER_SIZE * 8);
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+ return !ff_flac_decode_frame_header(avctx, &gb, fi, 127);
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+}
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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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+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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+ 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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+
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+ if (start >= f->end)
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+ start -= f->end - f->buffer;
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+ if (f->end - start >= len)
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+ return start;
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+
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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;
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+ }
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+ *wrap_buf = tmp_buf;
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+ do {
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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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+
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+ start += seg_len - (f->end - f->buffer);
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+ len -= seg_len;
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+ } while (len > 0);
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+
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+ return *wrap_buf;
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+}
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+
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+/**
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+ * Return a pointer in the fifo buffer where the offset starts at until
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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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+ **/
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+static uint8_t* flac_fifo_read(FLACParseContext *fpc, int offset, int *len)
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+{
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+ AVFifoBuffer *f = fpc->fifo_buf;
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+ uint8_t *start = f->rptr + offset;
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+
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+ if (start >= f->end)
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+ start -= f->end - f->buffer;
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+ *len = FFMIN(*len, f->end - start);
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+ return start;
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+}
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+
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+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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+ int size = 0;
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+ 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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+ if (frame_header_is_valid(fpc->avctx, header_buf, &fi)) {
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+ FLACHeaderMarker **end_handle = &fpc->headers;
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+ int i;
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+
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+ size = 0;
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+ while (*end_handle) {
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+ end_handle = &(*end_handle)->next;
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+ size++;
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+ }
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+
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+ *end_handle = av_mallocz(sizeof(FLACHeaderMarker));
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+ if (!*end_handle) {
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+ av_log(fpc->avctx, AV_LOG_ERROR,
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+ "couldn't allocate FLACHeaderMarker\n");
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+ return AVERROR(ENOMEM);
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+ }
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+ (*end_handle)->fi = fi;
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+ (*end_handle)->offset = offset;
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+ (*end_handle)->link_penalty = av_malloc(sizeof(int) *
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+ FLAC_MAX_SEQUENTIAL_HEADERS);
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+ for (i = 0; i < FLAC_MAX_SEQUENTIAL_HEADERS; i++)
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+ (*end_handle)->link_penalty[i] = FLAC_HEADER_NOT_PENALIZED_YET;
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+
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+ fpc->nb_headers_found++;
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+ size++;
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+ }
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+ return size;
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+}
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+
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+static int find_headers_search(FLACParseContext *fpc, uint8_t *buf, int buf_size,
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+ int search_start)
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+
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+{
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+ int size = 0, mod_offset = (buf_size - 1) % 4, i, j;
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+ uint32_t x;
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+
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+ for (i = 0; i < mod_offset; i++) {
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+ if ((AV_RB16(buf + i) & 0xFFFE) == 0xFFF8)
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+ size = find_headers_search_validate(fpc, search_start + i);
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+ }
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+
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+ for (; i < buf_size - 1; i += 4) {
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+ x = AV_RB32(buf + i);
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+ if (((x & ~(x + 0x01010101)) & 0x80808080)) {
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+ for (j = 0; j < 4; j++) {
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+ if ((AV_RB16(buf + i + j) & 0xFFFE) == 0xFFF8)
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+ size = find_headers_search_validate(fpc, search_start + i + j);
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+ }
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+ }
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+ }
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+ return size;
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+}
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+
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+static int find_new_headers(FLACParseContext *fpc, int search_start)
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+{
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+ FLACHeaderMarker *end;
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+ int search_end, size = 0, read_len, temp;
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+ uint8_t *buf;
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+ fpc->nb_headers_found = 0;
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+
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+ /* Search for a new header of at most 16 bytes. */
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+ search_end = av_fifo_size(fpc->fifo_buf) - (MAX_FRAME_HEADER_SIZE - 1);
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+ read_len = search_end - search_start + 1;
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+ buf = flac_fifo_read(fpc, search_start, &read_len);
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+ size = find_headers_search(fpc, buf, read_len, search_start);
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+ search_start += read_len - 1;
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+
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+ /* If fifo end was hit do the wrap around. */
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+ if (search_start != search_end) {
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+ uint8_t wrap[2];
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+
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+ wrap[0] = buf[read_len - 1];
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+ read_len = search_end - search_start + 1;
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+
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+ /* search_start + 1 is the post-wrap offset in the fifo. */
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+ buf = flac_fifo_read(fpc, search_start + 1, &read_len);
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+ wrap[1] = buf[0];
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+
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+ if ((AV_RB16(wrap) & 0xFFFE) == 0xFFF8) {
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+ temp = find_headers_search_validate(fpc, search_start);
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+ size = FFMAX(size, temp);
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+ }
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+ search_start++;
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+
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+ /* Continue to do the last half of the wrap. */
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+ temp = find_headers_search(fpc, buf, read_len, search_start);
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+ size = FFMAX(size, temp);
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+ search_start += read_len - 1;
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+ }
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+
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+ /* Return the size even if no new headers were found. */
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+ if (!size && fpc->headers)
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+ for (end = fpc->headers; end; end = end->next)
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+ size++;
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+ return size;
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+}
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+
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+static int check_header_mismatch(FLACParseContext *fpc,
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+ FLACHeaderMarker *header,
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+ FLACHeaderMarker *child,
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+ int log_level_offset)
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+{
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+ FLACFrameInfo *header_fi = &header->fi, *child_fi = &child->fi;
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+ int deduction = 0, deduction_expected = 0, i;
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+ if (child_fi->samplerate != header_fi->samplerate) {
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+ deduction += FLAC_HEADER_CHANGED_PENALTY;
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+ av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset,
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+ "sample rate change detected in adjacent frames\n");
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+ }
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+ if (child_fi->bps != header_fi->bps) {
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+ deduction += FLAC_HEADER_CHANGED_PENALTY;
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+ av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset,
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+ "bits per sample change detected in adjacent frames\n");
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+ }
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+ if (child_fi->is_var_size != header_fi->is_var_size) {
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+ /* Changing blocking strategy not allowed per the spec */
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+ deduction += FLAC_HEADER_BASE_SCORE;
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+ av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset,
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+ "blocking strategy change detected in adjacent frames\n");
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+ }
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+ if (child_fi->channels != header_fi->channels) {
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+ deduction += FLAC_HEADER_CHANGED_PENALTY;
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+ av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset,
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+ "number of channels change detected in adjacent frames\n");
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+ }
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+ /* Check sample and frame numbers. */
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+ if ((child_fi->frame_or_sample_num - header_fi->frame_or_sample_num
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+ != header_fi->blocksize) &&
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+ (child_fi->frame_or_sample_num
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+ != header_fi->frame_or_sample_num + 1)) {
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+ FLACHeaderMarker *curr;
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+ int expected_frame_num, expected_sample_num;
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+ /* If there are frames in the middle we expect this deduction,
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+ as they are probably valid and this one follows it */
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+
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+ expected_frame_num = expected_sample_num = header_fi->frame_or_sample_num;
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+ curr = header;
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+ while (curr != child) {
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+ /* Ignore frames that failed all crc checks */
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+ for (i = 0; i < FLAC_MAX_SEQUENTIAL_HEADERS; i++) {
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+ if (curr->link_penalty[i] < FLAC_HEADER_CRC_FAIL_PENALTY) {
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+ expected_frame_num++;
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+ expected_sample_num += curr->fi.blocksize;
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+ break;
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+ }
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+ }
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+ curr = curr->next;
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+ }
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+
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+ if (expected_frame_num == child_fi->frame_or_sample_num ||
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+ expected_sample_num == child_fi->frame_or_sample_num)
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+ deduction_expected = deduction ? 0 : 1;
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+
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+ deduction += FLAC_HEADER_CHANGED_PENALTY;
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+ av_log(fpc->avctx, AV_LOG_WARNING + log_level_offset,
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+ "sample/frame number mismatch in adjacent frames\n");
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+ }
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+
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+ /* If we have suspicious headers, check the CRC between them */
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+ if (deduction && !deduction_expected) {
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+ FLACHeaderMarker *curr;
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+ int read_len;
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+ uint8_t *buf;
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+ uint32_t crc = 1;
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+ int inverted_test = 0;
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+
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+ /* Since CRC is expensive only do it if we haven't yet.
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+ This assumes a CRC penalty is greater than all other check penalties */
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+ curr = header->next;
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+ for (i = 0; i < FLAC_MAX_SEQUENTIAL_HEADERS && curr != child; i++)
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+ curr = curr->next;
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+
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+ if (header->link_penalty[i] < FLAC_HEADER_CRC_FAIL_PENALTY ||
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+ header->link_penalty[i] == FLAC_HEADER_NOT_PENALIZED_YET) {
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+ FLACHeaderMarker *start, *end;
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+
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+ /* Although overlapping chains are scored, the crc should never
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+ have to be computed twice for a single byte. */
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+ start = header;
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+ end = child;
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+ if (i > 0 &&
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+ header->link_penalty[i - 1] >= FLAC_HEADER_CRC_FAIL_PENALTY) {
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+ while (start->next != child)
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+ start = start->next;
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+ inverted_test = 1;
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+ } else if (i > 0 &&
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+ header->next->link_penalty[i-1] >=
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+ FLAC_HEADER_CRC_FAIL_PENALTY ) {
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+ end = header->next;
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+ inverted_test = 1;
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+ }
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+
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+ read_len = end->offset - start->offset;
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+ buf = flac_fifo_read(fpc, start->offset, &read_len);
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+ crc = av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, buf, read_len);
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+ read_len = (end->offset - start->offset) - read_len;
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+
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+ if (read_len) {
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+ buf = flac_fifo_read(fpc, end->offset - read_len, &read_len);
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+ crc = av_crc(av_crc_get_table(AV_CRC_16_ANSI), crc, buf, read_len);
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+ }
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+ }
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+
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|
+ 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;
|
|
|
+
|
|
|
+ if (header->max_score != FLAC_HEADER_NOT_SCORED_YET)
|
|
|
+ return header->max_score;
|
|
|
+
|
|
|
+ header->max_score = FLAC_HEADER_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 = FLAC_HEADER_BASE_SCORE + child_score;
|
|
|
+ }
|
|
|
+ child = child->next;
|
|
|
+ }
|
|
|
+
|
|
|
+ return header->max_score;
|
|
|
+}
|
|
|
+
|
|
|
+static void score_sequences(FLACParseContext *fpc)
|
|
|
+{
|
|
|
+ FLACHeaderMarker *curr;
|
|
|
+ int best_score = 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);
|
|
|
+ }
|
|
|
+
|
|
|
+ fpc->avctx->sample_rate = header->fi.samplerate;
|
|
|
+ fpc->avctx->channels = header->fi.channels;
|
|
|
+ fpc->avctx->frame_size = 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;
|
|
|
+ /* 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;
|
|
|
+
|
|
|
+ if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
|
|
|
+ FLACFrameInfo fi;
|
|
|
+ if (frame_header_is_valid(avctx, buf, &fi))
|
|
|
+ avctx->frame_size = 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);
|
|
|
+ }
|
|
|
+ /* 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;
|
|
|
+
|
|
|
+ best_child->offset = 0;
|
|
|
+ fpc->headers = best_child;
|
|
|
+ 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. */
|
|
|
+ if (buf_size || !fpc->end_padded) {
|
|
|
+ int start_offset;
|
|
|
+
|
|
|
+ /* Pad the end once if EOF, to check the final region for headers. */
|
|
|
+ if (!buf_size) {
|
|
|
+ fpc->end_padded = 1;
|
|
|
+ buf_size = MAX_FRAME_HEADER_SIZE;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* Fill the buffer. */
|
|
|
+ if (av_fifo_realloc2(fpc->fifo_buf,
|
|
|
+ buf_size + av_fifo_size(fpc->fifo_buf)) < 0) {
|
|
|
+ av_log(avctx, AV_LOG_ERROR,
|
|
|
+ "couldn't reallocate buffer of size %d\n",
|
|
|
+ buf_size + av_fifo_size(fpc->fifo_buf));
|
|
|
+ goto handle_error;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (buf) {
|
|
|
+ av_fifo_generic_write(fpc->fifo_buf, (void*) buf, buf_size, NULL);
|
|
|
+ } else {
|
|
|
+ int8_t pad[MAX_FRAME_HEADER_SIZE];
|
|
|
+ memset(pad, 0, sizeof(pad));
|
|
|
+ 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) -
|
|
|
+ (buf_size + (MAX_FRAME_HEADER_SIZE - 1));
|
|
|
+ start_offset = FFMAX(0, start_offset);
|
|
|
+ nb_headers = find_new_headers(fpc, start_offset);
|
|
|
+
|
|
|
+ /* Wait till FLAC_MIN_HEADERS to output a valid frame. */
|
|
|
+ if (!fpc->end_padded && nb_headers < FLAC_MIN_HEADERS)
|
|
|
+ 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) {
|
|
|
+ /* HACK: drain the tail of the fifo */
|
|
|
+ fpc->fifo_buf->wptr -= MAX_FRAME_HEADER_SIZE;
|
|
|
+ fpc->fifo_buf->wndx -= MAX_FRAME_HEADER_SIZE;
|
|
|
+ if (fpc->fifo_buf->wptr < 0) {
|
|
|
+ fpc->fifo_buf->wptr += fpc->fifo_buf->end -
|
|
|
+ fpc->fifo_buf->buffer;
|
|
|
+ }
|
|
|
+ buf_size = 0;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ curr = fpc->headers;
|
|
|
+ for (curr = fpc->headers; curr; curr = curr->next)
|
|
|
+ if (!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 frame_size to 0. It is unknown or invalid in a junk frame. */
|
|
|
+ avctx->frame_size = 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 ? buf_size : (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;
|
|
|
+}
|
|
|
+
|
|
|
+static int flac_parse_init(AVCodecParserContext *c)
|
|
|
+{
|
|
|
+ FLACParseContext *fpc = c->priv_data;
|
|
|
+ /* There will generally be FLAC_MIN_HEADERS buffered in the fifo before
|
|
|
+ it drains. 8192 is an approximate average size of a flac frame */
|
|
|
+ fpc->fifo_buf = av_fifo_alloc(8192 * FLAC_MIN_HEADERS);
|
|
|
+
|
|
|
+ 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 flac_parser = {
|
|
|
+ { CODEC_ID_FLAC },
|
|
|
+ sizeof(FLACParseContext),
|
|
|
+ flac_parse_init,
|
|
|
+ flac_parse,
|
|
|
+ flac_parse_close,
|
|
|
+};
|
Michael Chinen