tak_parser: properly mark packets as key frames
[ffmpeg.git] / libavcodec / tak_parser.c
1 /*
2  * TAK parser
3  * Copyright (c) 2012 Michael Niedermayer
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21
22 /**
23  * @file
24  * TAK parser
25  **/
26
27 #include "tak.h"
28 #include "parser.h"
29
30 typedef struct TAKParseContext {
31     ParseContext  pc;
32     TAKStreamInfo ti;
33     int           index;
34 } TAKParseContext;
35
36 static av_cold int tak_init(AVCodecParserContext *s)
37 {
38     ff_tak_init_crc();
39     return 0;
40 }
41
42 static int tak_parse(AVCodecParserContext *s, AVCodecContext *avctx,
43                      const uint8_t **poutbuf, int *poutbuf_size,
44                      const uint8_t *buf, int buf_size)
45 {
46     TAKParseContext *t = s->priv_data;
47     ParseContext *pc   = &t->pc;
48     int next           = END_NOT_FOUND;
49     GetBitContext gb;
50     int consumed = 0;
51     int needed   = buf_size ? TAK_MAX_FRAME_HEADER_BYTES : 8;
52
53     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
54         TAKStreamInfo ti;
55         init_get_bits(&gb, buf, buf_size);
56         if (!ff_tak_decode_frame_header(avctx, &gb, &ti, 127))
57             s->duration = t->ti.last_frame_samples ? t->ti.last_frame_samples
58                                                    : t->ti.frame_samples;
59         *poutbuf      = buf;
60         *poutbuf_size = buf_size;
61         return buf_size;
62     }
63
64     while (buf_size || t->index + needed <= pc->index) {
65         if (buf_size && t->index + TAK_MAX_FRAME_HEADER_BYTES > pc->index) {
66             int tmp_buf_size       = FFMIN(2 * TAK_MAX_FRAME_HEADER_BYTES,
67                                            buf_size);
68             const uint8_t *tmp_buf = buf;
69
70             if (ff_combine_frame(pc, END_NOT_FOUND, &tmp_buf, &tmp_buf_size) != -1)
71                 return AVERROR(ENOMEM);
72             consumed += tmp_buf_size;
73             buf      += tmp_buf_size;
74             buf_size -= tmp_buf_size;
75         }
76
77         for (; t->index + needed <= pc->index; t->index++) {
78             if (pc->buffer[ t->index     ] == 0xFF &&
79                 pc->buffer[ t->index + 1 ] == 0xA0) {
80                 TAKStreamInfo ti;
81
82                 init_get_bits(&gb, pc->buffer + t->index,
83                               8 * (pc->index - t->index));
84                 if (!ff_tak_decode_frame_header(avctx, &gb,
85                         pc->frame_start_found ? &ti : &t->ti, 127) &&
86                     !ff_tak_check_crc(pc->buffer + t->index,
87                                       get_bits_count(&gb) / 8)) {
88                     if (!pc->frame_start_found) {
89                         pc->frame_start_found = 1;
90                         s->duration           = t->ti.last_frame_samples ?
91                                                 t->ti.last_frame_samples :
92                                                 t->ti.frame_samples;
93                         s->key_frame          = !!(t->ti.flags & TAK_FRAME_FLAG_HAS_INFO);
94                     } else {
95                         pc->frame_start_found = 0;
96                         next                  = t->index - pc->index;
97                         t->index              = 0;
98                         goto found;
99                     }
100                 }
101             }
102         }
103     }
104 found:
105
106     if (consumed && !buf_size && next == END_NOT_FOUND ||
107         ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
108         *poutbuf      = NULL;
109         *poutbuf_size = 0;
110         return buf_size + consumed;
111     }
112
113     if (next != END_NOT_FOUND) {
114         next        += consumed;
115         pc->overread = FFMAX(0, -next);
116     }
117
118     *poutbuf      = buf;
119     *poutbuf_size = buf_size;
120     return next;
121 }
122
123 AVCodecParser ff_tak_parser = {
124     .codec_ids      = { AV_CODEC_ID_TAK },
125     .priv_data_size = sizeof(TAKParseContext),
126     .parser_init    = tak_init,
127     .parser_parse   = tak_parse,
128     .parser_close   = ff_parse_close,
129 };