new mtv demuxer
[libav.git] / libavformat / mtv.c
CommitLineData
28146a8c
RVP
1/*
2 * mtv demuxer
3 * Copyright (c) 2006 Reynaldo H. Verdejo Pinochet
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 mtv.c
24 * MTV demuxer.
25 */
26
27#include "avformat.h"
28#include "bswap.h"
29
30#define MTV_ASUBCHUNK_DATA_SIZE 500
31#define MTV_HEADER_SIZE 512
32#define MTV_AUDIO_PADDING_SIZE 12
33#define AUDIO_SAMPLING_RATE 44100
34#define VIDEO_SID 0
35#define AUDIO_SID 1
36
37typedef struct MTVDemuxContext {
38
39 unsigned int file_size; ///< filesize, not always right
40 unsigned int segments; ///< number of 512 byte segments
41 unsigned int audio_identifier; ///< 'MP3' on all files I have seen
42 unsigned int audio_br; ///< bitrate of audio chanel (mp3)
43 unsigned int img_colorfmt; ///< frame colorfmt rgb 565/555
44 unsigned int img_bpp; ///< frame bits per pixel
45 unsigned int img_width; //
46 unsigned int img_height; //
47 unsigned int img_segment_size; ///< size of image segment
48 unsigned int video_fps; //
49 unsigned int audio_subsegments; ///< audio subsegments on one segment
50
51 uint8_t audio_packet_count;
52
53} MTVDemuxContext;
54
55static int mtv_probe(AVProbeData *p)
56{
57 if(p->buf_size < 3)
58 return 0;
59
60 /* Magic is 'AMV' */
61
62 if(*(p->buf) != 'A' || *(p->buf+1) != 'M' || *(p->buf+2) != 'V')
63 return 0;
64
65 return AVPROBE_SCORE_MAX;
66}
67
68static int mtv_read_header(AVFormatContext *s, AVFormatParameters *ap)
69{
70 MTVDemuxContext *mtv = s->priv_data;
71 ByteIOContext *pb = &s->pb;
72 AVStream *st;
73
74
75 url_fskip(pb, 3);
76 mtv->file_size = get_le32(pb);
77 mtv->segments = get_le32(pb);
78 url_fskip(pb, 32);
79 mtv->audio_identifier = get_le24(pb);
80 mtv->audio_br = get_le16(pb);
81 mtv->img_colorfmt = get_le24(pb);
82 mtv->img_bpp = get_byte(pb);
83 mtv->img_width = get_le16(pb);
84 mtv->img_height = get_le16(pb);
85 mtv->img_segment_size = get_le16(pb);
86 url_fskip(pb, 4);
87 mtv->audio_subsegments = get_le16(pb);
88 mtv->video_fps = (mtv->audio_br / 4) / mtv->audio_subsegments;
89
90 /* FIXME Add sanity check here */
91
92 /* first packet is allways audio*/
93
94 mtv->audio_packet_count = 1;
95
96 /* all systems go! init decoders */
97
98 /* video - raw rgb565 */
99
100 st = av_new_stream(s, VIDEO_SID);
101 if(!st)
102 return AVERROR_NOMEM;
103
104 av_set_pts_info(st, 64, 1, mtv->video_fps);
105 st->codec->codec_type = CODEC_TYPE_VIDEO;
106 st->codec->codec_id = CODEC_ID_RAWVIDEO;
107 st->codec->width = mtv->img_width;
108 st->codec->height = mtv->img_height;
109 st->codec->bits_per_sample = mtv->img_bpp;
110 st->codec->sample_rate = mtv->video_fps;
111
112 /* audio - mp3 */
113
114 st = av_new_stream(s, AUDIO_SID);
115 if(!st)
116 return AVERROR_NOMEM;
117
118 av_set_pts_info(st, 64, 1, AUDIO_SAMPLING_RATE);
119 st->codec->codec_type = CODEC_TYPE_AUDIO;
120 st->codec->codec_id = CODEC_ID_MP3;
121 st->codec->bit_rate = mtv->audio_br;
122 st->need_parsing=1;
123
124 /* Jump over header */
125
126 if(url_fseek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE)
127 return AVERROR_IO;
128
129 return(0);
130
131}
132
133static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt)
134{
135 MTVDemuxContext *mtv = s->priv_data;
136 ByteIOContext *pb = &s->pb;
137 int ret;
138#ifndef WORDS_BIGENDIAN
139 int i;
140#endif
141
142 ret = 0;
143
144 if(mtv->audio_subsegments >= mtv->audio_packet_count)
145 {
146 url_fskip(pb, MTV_AUDIO_PADDING_SIZE);
147
148 ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE);
149 if(ret != MTV_ASUBCHUNK_DATA_SIZE)
150 return AVERROR_IO;
151
152 mtv->audio_packet_count++;
153 pkt->stream_index = AUDIO_SID;
154
155 }else
156 {
157 ret = av_get_packet(pb, pkt, mtv->img_segment_size);
158 if(ret != mtv->img_segment_size)
159 return AVERROR_IO;
160
161#ifndef WORDS_BIGENDIAN
162
163 /* pkt->data is GGGRRRR BBBBBGGG
164 * and we need RRRRRGGG GGGBBBBB
165 * for PIX_FMT_RGB565 so here we
166 * just swap bytes as they come
167 */
168
169 for(i=0;i<mtv->img_segment_size/2;i++)
170 *((uint16_t *)pkt->data+i) = bswap_16(*((uint16_t *)pkt->data+i));
171#endif
172 mtv->audio_packet_count = 1;
173 pkt->stream_index = VIDEO_SID;
174 }
175
176 return(ret);
177}
178
179AVInputFormat mtv_demuxer = {
180 "MTV",
181 "MTV format",
182 sizeof(MTVDemuxContext),
183 mtv_probe,
184 mtv_read_header,
185 mtv_read_packet,
186};