Improve error message in case of output file with no streams, dumping
[libav.git] / libavformat / mtv.c
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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
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; //
ddca6ab6 49 unsigned int full_segment_size;
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50
51} MTVDemuxContext;
52
53static int mtv_probe(AVProbeData *p)
54{
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55 /* Magic is 'AMV' */
56
57 if(*(p->buf) != 'A' || *(p->buf+1) != 'M' || *(p->buf+2) != 'V')
58 return 0;
59
60 return AVPROBE_SCORE_MAX;
61}
62
63static int mtv_read_header(AVFormatContext *s, AVFormatParameters *ap)
64{
65 MTVDemuxContext *mtv = s->priv_data;
899681cd 66 ByteIOContext *pb = s->pb;
28146a8c 67 AVStream *st;
ddca6ab6 68 unsigned int audio_subsegments;
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69
70
71 url_fskip(pb, 3);
72 mtv->file_size = get_le32(pb);
73 mtv->segments = get_le32(pb);
74 url_fskip(pb, 32);
75 mtv->audio_identifier = get_le24(pb);
76 mtv->audio_br = get_le16(pb);
77 mtv->img_colorfmt = get_le24(pb);
78 mtv->img_bpp = get_byte(pb);
79 mtv->img_width = get_le16(pb);
80 mtv->img_height = get_le16(pb);
81 mtv->img_segment_size = get_le16(pb);
82 url_fskip(pb, 4);
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83 audio_subsegments = get_le16(pb);
84 mtv->full_segment_size =
85 audio_subsegments * (MTV_AUDIO_PADDING_SIZE + MTV_ASUBCHUNK_DATA_SIZE) +
86 mtv->img_segment_size;
87 mtv->video_fps = (mtv->audio_br / 4) / audio_subsegments;
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88
89 /* FIXME Add sanity check here */
90
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91 /* all systems go! init decoders */
92
93 /* video - raw rgb565 */
94
95 st = av_new_stream(s, VIDEO_SID);
96 if(!st)
769e10f0 97 return AVERROR(ENOMEM);
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98
99 av_set_pts_info(st, 64, 1, mtv->video_fps);
100 st->codec->codec_type = CODEC_TYPE_VIDEO;
101 st->codec->codec_id = CODEC_ID_RAWVIDEO;
b1d196db 102 st->codec->codec_tag = MKTAG('R', 'G', 'B', mtv->img_bpp);
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103 st->codec->width = mtv->img_width;
104 st->codec->height = mtv->img_height;
dd1c8f3e 105 st->codec->bits_per_coded_sample = mtv->img_bpp;
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106 st->codec->sample_rate = mtv->video_fps;
107
108 /* audio - mp3 */
109
110 st = av_new_stream(s, AUDIO_SID);
111 if(!st)
769e10f0 112 return AVERROR(ENOMEM);
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113
114 av_set_pts_info(st, 64, 1, AUDIO_SAMPLING_RATE);
115 st->codec->codec_type = CODEC_TYPE_AUDIO;
116 st->codec->codec_id = CODEC_ID_MP3;
117 st->codec->bit_rate = mtv->audio_br;
57004ff1 118 st->need_parsing = AVSTREAM_PARSE_FULL;
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119
120 /* Jump over header */
121
122 if(url_fseek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE)
6f3e0b21 123 return AVERROR(EIO);
28146a8c 124
ccd425e7 125 return 0;
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126
127}
128
129static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt)
130{
131 MTVDemuxContext *mtv = s->priv_data;
899681cd 132 ByteIOContext *pb = s->pb;
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133 int ret;
134#ifndef WORDS_BIGENDIAN
135 int i;
136#endif
137
138 ret = 0;
139
ddca6ab6 140 if((url_ftell(pb) - s->data_offset + mtv->img_segment_size) % mtv->full_segment_size)
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141 {
142 url_fskip(pb, MTV_AUDIO_PADDING_SIZE);
143
144 ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE);
145 if(ret != MTV_ASUBCHUNK_DATA_SIZE)
6f3e0b21 146 return AVERROR(EIO);
28146a8c 147
34bfe875 148 pkt->pos -= MTV_AUDIO_PADDING_SIZE;
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149 pkt->stream_index = AUDIO_SID;
150
151 }else
152 {
153 ret = av_get_packet(pb, pkt, mtv->img_segment_size);
154 if(ret != mtv->img_segment_size)
6f3e0b21 155 return AVERROR(EIO);
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156
157#ifndef WORDS_BIGENDIAN
158
159 /* pkt->data is GGGRRRR BBBBBGGG
160 * and we need RRRRRGGG GGGBBBBB
161 * for PIX_FMT_RGB565 so here we
162 * just swap bytes as they come
163 */
164
165 for(i=0;i<mtv->img_segment_size/2;i++)
166 *((uint16_t *)pkt->data+i) = bswap_16(*((uint16_t *)pkt->data+i));
167#endif
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168 pkt->stream_index = VIDEO_SID;
169 }
170
ccd425e7 171 return ret;
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172}
173
174AVInputFormat mtv_demuxer = {
175 "MTV",
bde15e74 176 NULL_IF_CONFIG_SMALL("MTV format"),
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177 sizeof(MTVDemuxContext),
178 mtv_probe,
179 mtv_read_header,
180 mtv_read_packet,
181};