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/get_bits.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_long(&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        if (!(st->codec->time_base.num > 0 && st->codec->time_base.den > 0)) {
90            av_log(s, AV_LOG_WARNING, "Invalid time base in theora stream, assuming 25 FPS\n");
91            st->codec->time_base.num = 1;
92            st->codec->time_base.den = 25;
93        }
94        st->time_base = st->codec->time_base;
95
96        st->sample_aspect_ratio.num = get_bits_long(&gb, 24);
97        st->sample_aspect_ratio.den = get_bits_long(&gb, 24);
98
99        if (thp->version >= 0x030200)
100            skip_bits_long(&gb, 38);
101        if (thp->version >= 0x304000)
102            skip_bits(&gb, 2);
103
104        thp->gpshift = get_bits(&gb, 5);
105        thp->gpmask = (1 << thp->gpshift) - 1;
106
107        st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
108        st->codec->codec_id = CODEC_ID_THEORA;
109        st->need_parsing = AVSTREAM_PARSE_HEADERS;
110
111    } else if (os->buf[os->pstart] == 0x83) {
112        ff_vorbis_comment (s, &st->metadata, os->buf + os->pstart + 7, os->psize - 8);
113    }
114
115    st->codec->extradata = av_realloc (st->codec->extradata,
116                                       cds + FF_INPUT_BUFFER_PADDING_SIZE);
117    cdp = st->codec->extradata + st->codec->extradata_size;
118    *cdp++ = os->psize >> 8;
119    *cdp++ = os->psize & 0xff;
120    memcpy (cdp, os->buf + os->pstart, os->psize);
121    st->codec->extradata_size = cds;
122
123    return 1;
124}
125
126static uint64_t
127theora_gptopts(AVFormatContext *ctx, int idx, uint64_t gp, int64_t *dts)
128{
129    struct ogg *ogg = ctx->priv_data;
130    struct ogg_stream *os = ogg->streams + idx;
131    struct theora_params *thp = os->private;
132    uint64_t iframe = gp >> thp->gpshift;
133    uint64_t pframe = gp & thp->gpmask;
134
135    if (thp->version < 0x030201)
136        iframe++;
137
138    if(!pframe)
139        os->pflags |= AV_PKT_FLAG_KEY;
140
141    if (dts)
142        *dts = iframe + pframe;
143
144    return iframe + pframe;
145}
146
147const struct ogg_codec ff_theora_codec = {
148    .magic = "\200theora",
149    .magicsize = 7,
150    .header = theora_header,
151    .gptopts = theora_gptopts
152};
153