COSMETICS
[libav.git] / libavformat / mtv.c
CommitLineData
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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
245976da 27#include "libavutil/bswap.h"
28146a8c 28#include "avformat.h"
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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
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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 full_segment_size;
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50
51} MTVDemuxContext;
52
53static int mtv_probe(AVProbeData *p)
54{
28146a8c 55 /* Magic is 'AMV' */
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56 if(*(p->buf) != 'A' || *(p->buf+1) != 'M' || *(p->buf+2) != 'V')
57 return 0;
58
59 return AVPROBE_SCORE_MAX;
60}
61
62static int mtv_read_header(AVFormatContext *s, AVFormatParameters *ap)
63{
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64 MTVDemuxContext *mtv = s->priv_data;
65 ByteIOContext *pb = s->pb;
66 AVStream *st;
67 unsigned int audio_subsegments;
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68
69 url_fskip(pb, 3);
70 mtv->file_size = get_le32(pb);
71 mtv->segments = get_le32(pb);
72 url_fskip(pb, 32);
73 mtv->audio_identifier = get_le24(pb);
74 mtv->audio_br = get_le16(pb);
75 mtv->img_colorfmt = get_le24(pb);
76 mtv->img_bpp = get_byte(pb);
77 mtv->img_width = get_le16(pb);
78 mtv->img_height = get_le16(pb);
79 mtv->img_segment_size = get_le16(pb);
80 url_fskip(pb, 4);
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81 audio_subsegments = get_le16(pb);
82 mtv->full_segment_size =
83 audio_subsegments * (MTV_AUDIO_PADDING_SIZE + MTV_ASUBCHUNK_DATA_SIZE) +
84 mtv->img_segment_size;
85 mtv->video_fps = (mtv->audio_br / 4) / audio_subsegments;
28146a8c 86
a45bdbc4 87 // FIXME Add sanity check here
28146a8c 88
a45bdbc4 89 // all systems go! init decoders
28146a8c 90
a45bdbc4 91 // video - raw rgb565
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92
93 st = av_new_stream(s, VIDEO_SID);
94 if(!st)
769e10f0 95 return AVERROR(ENOMEM);
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96
97 av_set_pts_info(st, 64, 1, mtv->video_fps);
98 st->codec->codec_type = CODEC_TYPE_VIDEO;
99 st->codec->codec_id = CODEC_ID_RAWVIDEO;
b1d196db 100 st->codec->codec_tag = MKTAG('R', 'G', 'B', mtv->img_bpp);
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101 st->codec->width = mtv->img_width;
102 st->codec->height = mtv->img_height;
dd1c8f3e 103 st->codec->bits_per_coded_sample = mtv->img_bpp;
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104 st->codec->sample_rate = mtv->video_fps;
105
a45bdbc4 106 // audio - mp3
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107
108 st = av_new_stream(s, AUDIO_SID);
109 if(!st)
769e10f0 110 return AVERROR(ENOMEM);
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111
112 av_set_pts_info(st, 64, 1, AUDIO_SAMPLING_RATE);
113 st->codec->codec_type = CODEC_TYPE_AUDIO;
114 st->codec->codec_id = CODEC_ID_MP3;
115 st->codec->bit_rate = mtv->audio_br;
57004ff1 116 st->need_parsing = AVSTREAM_PARSE_FULL;
28146a8c 117
a45bdbc4 118 // Jump over header
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119
120 if(url_fseek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE)
6f3e0b21 121 return AVERROR(EIO);
28146a8c 122
ccd425e7 123 return 0;
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124
125}
126
127static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt)
128{
129 MTVDemuxContext *mtv = s->priv_data;
899681cd 130 ByteIOContext *pb = s->pb;
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131 int ret;
132#ifndef WORDS_BIGENDIAN
133 int i;
134#endif
135
136 ret = 0;
137
ddca6ab6 138 if((url_ftell(pb) - s->data_offset + mtv->img_segment_size) % mtv->full_segment_size)
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139 {
140 url_fskip(pb, MTV_AUDIO_PADDING_SIZE);
141
142 ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE);
143 if(ret != MTV_ASUBCHUNK_DATA_SIZE)
6f3e0b21 144 return AVERROR(EIO);
28146a8c 145
34bfe875 146 pkt->pos -= MTV_AUDIO_PADDING_SIZE;
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147 pkt->stream_index = AUDIO_SID;
148
149 }else
150 {
151 ret = av_get_packet(pb, pkt, mtv->img_segment_size);
152 if(ret != mtv->img_segment_size)
6f3e0b21 153 return AVERROR(EIO);
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154
155#ifndef WORDS_BIGENDIAN
156
157 /* pkt->data is GGGRRRR BBBBBGGG
158 * and we need RRRRRGGG GGGBBBBB
159 * for PIX_FMT_RGB565 so here we
160 * just swap bytes as they come
161 */
162
163 for(i=0;i<mtv->img_segment_size/2;i++)
164 *((uint16_t *)pkt->data+i) = bswap_16(*((uint16_t *)pkt->data+i));
165#endif
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166 pkt->stream_index = VIDEO_SID;
167 }
168
ccd425e7 169 return ret;
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170}
171
172AVInputFormat mtv_demuxer = {
173 "MTV",
bde15e74 174 NULL_IF_CONFIG_SMALL("MTV format"),
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175 sizeof(MTVDemuxContext),
176 mtv_probe,
177 mtv_read_header,
178 mtv_read_packet,
179};