1/**
2      Copyright (C) 2005  Matthieu CASTET, Alex Beregszaszi
3
4      Permission is hereby granted, free of charge, to any person
5      obtaining a copy of this software and associated documentation
6      files (the "Software"), to deal in the Software without
7      restriction, including without limitation the rights to use, copy,
8      modify, merge, publish, distribute, sublicense, and/or sell copies
9      of the Software, and to permit persons to whom the Software is
10      furnished to do so, subject to the following conditions:
11
12      The above copyright notice and this permission notice shall be
13      included in all copies or substantial portions of the Software.
14
15      THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16      EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17      MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18      NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
19      HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
20      WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21      OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22      DEALINGS IN THE SOFTWARE.
23**/
24
25#include <stdlib.h>
26#include "libavutil/bswap.h"
27#include "libavcodec/bitstream.h"
28#include "avformat.h"
29#include "oggdec.h"
30
31struct theora_params {
32    int gpshift;
33    int gpmask;
34    unsigned version;
35};
36
37static int
38theora_header (AVFormatContext * s, int idx)
39{
40    struct ogg *ogg = s->priv_data;
41    struct ogg_stream *os = ogg->streams + idx;
42    AVStream *st = s->streams[idx];
43    struct theora_params *thp = os->private;
44    int cds = st->codec->extradata_size + os->psize + 2;
45    uint8_t *cdp;
46
47    if(!(os->buf[os->pstart] & 0x80))
48        return 0;
49
50    if(!thp){
51        thp = av_mallocz(sizeof(*thp));
52        os->private = thp;
53    }
54
55    if (os->buf[os->pstart] == 0x80) {
56        GetBitContext gb;
57        int width, height;
58
59        init_get_bits(&gb, os->buf + os->pstart, os->psize*8);
60
61        skip_bits(&gb, 7*8); /* 0x80"theora" */
62
63        thp->version = get_bits_long(&gb, 24);
64        if (thp->version < 0x030100)
65        {
66            av_log(s, AV_LOG_ERROR,
67                "Too old or unsupported Theora (%x)\n", thp->version);
68            return -1;
69        }
70
71        width  = get_bits(&gb, 16) << 4;
72        height = get_bits(&gb, 16) << 4;
73        avcodec_set_dimensions(st->codec, width, height);
74
75        if (thp->version >= 0x030400)
76            skip_bits(&gb, 100);
77
78        if (thp->version >= 0x030200) {
79            width  = get_bits_long(&gb, 24);
80            height = get_bits_long(&gb, 24);
81            if (   width  <= st->codec->width  && width  > st->codec->width-16
82                && height <= st->codec->height && height > st->codec->height-16)
83                avcodec_set_dimensions(st->codec, width, height);
84
85            skip_bits(&gb, 16);
86        }
87        st->codec->time_base.den = get_bits_long(&gb, 32);
88        st->codec->time_base.num = get_bits_long(&gb, 32);
89        st->time_base = st->codec->time_base;
90
91        st->sample_aspect_ratio.num = get_bits_long(&gb, 24);
92        st->sample_aspect_ratio.den = get_bits_long(&gb, 24);
93
94        if (thp->version >= 0x030200)
95            skip_bits(&gb, 38);
96        if (thp->version >= 0x304000)
97            skip_bits(&gb, 2);
98
99        thp->gpshift = get_bits(&gb, 5);
100        thp->gpmask = (1 << thp->gpshift) - 1;
101
102        st->codec->codec_type = CODEC_TYPE_VIDEO;
103        st->codec->codec_id = CODEC_ID_THEORA;
104
105    } else if (os->buf[os->pstart] == 0x83) {
106        vorbis_comment (s, os->buf + os->pstart + 7, os->psize - 8);
107    }
108
109    st->codec->extradata = av_realloc (st->codec->extradata, cds);
110    cdp = st->codec->extradata + st->codec->extradata_size;
111    *cdp++ = os->psize >> 8;
112    *cdp++ = os->psize & 0xff;
113    memcpy (cdp, os->buf + os->pstart, os->psize);
114    st->codec->extradata_size = cds;
115
116    return 1;
117}
118
119static uint64_t
120theora_gptopts(AVFormatContext *ctx, int idx, uint64_t gp)
121{
122    struct ogg *ogg = ctx->priv_data;
123    struct ogg_stream *os = ogg->streams + idx;
124    struct theora_params *thp = os->private;
125    uint64_t iframe = gp >> thp->gpshift;
126    uint64_t pframe = gp & thp->gpmask;
127
128    if (thp->version < 0x030201)
129        iframe++;
130
131    if(!pframe)
132        os->pflags |= PKT_FLAG_KEY;
133
134    return iframe + pframe;
135}
136
137const struct ogg_codec ff_theora_codec = {
138    .magic = "\200theora",
139    .magicsize = 7,
140    .header = theora_header,
141    .gptopts = theora_gptopts
142};
143