Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / vp9_parser.c
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1/*
2 * Copyright (C) 2008 Michael Niedermayer
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include "libavutil/intreadwrite.h"
22#include "parser.h"
23
24typedef struct VP9ParseContext {
25 int n_frames; // 1-8
26 int size[8];
27} VP9ParseContext;
28
29static void parse_frame(AVCodecParserContext *ctx, const uint8_t *buf, int size)
30{
31 if (buf[0] & 0x4) {
32 ctx->pict_type = AV_PICTURE_TYPE_P;
33 ctx->key_frame = 0;
34 } else {
35 ctx->pict_type = AV_PICTURE_TYPE_I;
36 ctx->key_frame = 1;
37 }
38}
39
40static int parse(AVCodecParserContext *ctx,
41 AVCodecContext *avctx,
42 const uint8_t **out_data, int *out_size,
43 const uint8_t *data, int size)
44{
45 VP9ParseContext *s = ctx->priv_data;
46 int marker;
47
48 if (size <= 0) {
49 *out_size = 0;
50 *out_data = data;
51
52 return 0;
53 }
54
55 if (s->n_frames > 0) {
56 *out_data = data;
57 *out_size = s->size[--s->n_frames];
58 parse_frame(ctx, *out_data, *out_size);
59
60 return s->n_frames > 0 ? *out_size : size /* i.e. include idx tail */;
61 }
62
63 marker = data[size - 1];
64 if ((marker & 0xe0) == 0xc0) {
65 int nbytes = 1 + ((marker >> 3) & 0x3);
66 int n_frames = 1 + (marker & 0x7), idx_sz = 2 + n_frames * nbytes;
67
68 if (size >= idx_sz && data[size - idx_sz] == marker) {
69 const uint8_t *idx = data + size + 1 - idx_sz;
70 int first = 1;
71
72 switch (nbytes) {
73#define case_n(a, rd) \
74 case a: \
75 while (n_frames--) { \
76 unsigned sz = rd; \
77 idx += a; \
78 if (sz > size) { \
79 s->n_frames = 0; \
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80 *out_size = 0; \
81 *out_data = data; \
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82 av_log(avctx, AV_LOG_ERROR, \
83 "Superframe packet size too big: %u > %d\n", \
84 sz, size); \
85 return size; \
86 } \
87 if (first) { \
88 first = 0; \
89 *out_data = data; \
90 *out_size = sz; \
91 s->n_frames = n_frames; \
92 } else { \
93 s->size[n_frames] = sz; \
94 } \
95 data += sz; \
96 size -= sz; \
97 } \
98 parse_frame(ctx, *out_data, *out_size); \
99 return *out_size
100
101 case_n(1, *idx);
102 case_n(2, AV_RL16(idx));
103 case_n(3, AV_RL24(idx));
104 case_n(4, AV_RL32(idx));
105 }
106 }
107 }
108
109 *out_data = data;
110 *out_size = size;
111 parse_frame(ctx, data, size);
112
113 return size;
114}
115
116AVCodecParser ff_vp9_parser = {
117 .codec_ids = { AV_CODEC_ID_VP9 },
118 .priv_data_size = sizeof(VP9ParseContext),
119 .parser_parse = parse,
120};