xref: /third_party/ffmpeg/libavformat/bmv.c (revision cabdff1a)
1/*
2 * Discworld II BMV demuxer
3 * Copyright (c) 2011 Konstantin Shishkov
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#include "libavutil/channel_layout.h"
23#include "avformat.h"
24#include "internal.h"
25
26enum BMVFlags {
27    BMV_NOP = 0,
28    BMV_END,
29    BMV_DELTA,
30    BMV_INTRA,
31
32    BMV_AUDIO   = 0x20,
33};
34
35typedef struct BMVContext {
36    uint8_t *packet;
37    int      size;
38    int      get_next;
39    int64_t  audio_pos;
40} BMVContext;
41
42static int bmv_read_header(AVFormatContext *s)
43{
44    AVStream *st, *ast;
45    BMVContext *c = s->priv_data;
46
47    st = avformat_new_stream(s, 0);
48    if (!st)
49        return AVERROR(ENOMEM);
50    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
51    st->codecpar->codec_id   = AV_CODEC_ID_BMV_VIDEO;
52    st->codecpar->width      = 640;
53    st->codecpar->height     = 429;
54    st->codecpar->format     = AV_PIX_FMT_PAL8;
55    avpriv_set_pts_info(st, 16, 1, 12);
56    ast = avformat_new_stream(s, 0);
57    if (!ast)
58        return AVERROR(ENOMEM);
59    ast->codecpar->codec_type      = AVMEDIA_TYPE_AUDIO;
60    ast->codecpar->codec_id        = AV_CODEC_ID_BMV_AUDIO;
61    ast->codecpar->ch_layout       = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
62    ast->codecpar->sample_rate     = 22050;
63    avpriv_set_pts_info(ast, 16, 1, 22050);
64
65    c->get_next  = 1;
66    c->audio_pos = 0;
67    return 0;
68}
69
70static int bmv_read_packet(AVFormatContext *s, AVPacket *pkt)
71{
72    BMVContext *c = s->priv_data;
73    int type, err;
74
75    while (c->get_next) {
76        if (s->pb->eof_reached)
77            return AVERROR_EOF;
78        type = avio_r8(s->pb);
79        if (type == BMV_NOP)
80            continue;
81        if (type == BMV_END)
82            return AVERROR_EOF;
83        c->size = avio_rl24(s->pb);
84        if (!c->size)
85            return AVERROR_INVALIDDATA;
86        if ((err = av_reallocp(&c->packet, c->size + 1)) < 0)
87            return err;
88        c->packet[0] = type;
89        if (avio_read(s->pb, c->packet + 1, c->size) != c->size)
90            return AVERROR(EIO);
91        if (type & BMV_AUDIO) {
92            int audio_size = c->packet[1] * 65 + 1;
93            if (audio_size >= c->size) {
94                av_log(s, AV_LOG_ERROR, "Reported audio size %d is bigger than packet size (%d)\n",
95                       audio_size, c->size);
96                return AVERROR_INVALIDDATA;
97            }
98            if ((err = av_new_packet(pkt, audio_size)) < 0)
99                return err;
100            memcpy(pkt->data, c->packet + 1, pkt->size);
101            pkt->stream_index = 1;
102            pkt->pts          = c->audio_pos;
103            pkt->duration     = c->packet[1] * 32;
104            c->audio_pos += pkt->duration;
105            c->get_next   = 0;
106            return pkt->size;
107        } else
108            break;
109    }
110    if ((err = av_new_packet(pkt, c->size + 1)) < 0)
111        return err;
112    pkt->stream_index = 0;
113    c->get_next = 1;
114    memcpy(pkt->data, c->packet, pkt->size);
115    return pkt->size;
116}
117
118static int bmv_read_close(AVFormatContext *s)
119{
120    BMVContext *c = s->priv_data;
121
122    av_freep(&c->packet);
123
124    return 0;
125}
126
127const AVInputFormat ff_bmv_demuxer = {
128    .name           = "bmv",
129    .long_name      = NULL_IF_CONFIG_SMALL("Discworld II BMV"),
130    .priv_data_size = sizeof(BMVContext),
131    .read_header    = bmv_read_header,
132    .read_packet    = bmv_read_packet,
133    .read_close     = bmv_read_close,
134    .extensions     = "bmv",
135};
136