Imported Debian version 2.4.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavformat / mtv.c
CommitLineData
2ba45a60
DM
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
24 * MTV demuxer.
25 */
26
27#include "libavutil/bswap.h"
28#include "libavutil/intreadwrite.h"
29#include "avformat.h"
30#include "internal.h"
31
32#define MTV_ASUBCHUNK_DATA_SIZE 500
33#define MTV_HEADER_SIZE 512
34#define MTV_AUDIO_PADDING_SIZE 12
35#define MTV_IMAGE_DEFAULT_BPP 16
36#define MTV_AUDIO_SAMPLING_RATE 44100
37
38typedef struct MTVDemuxContext {
39
40 unsigned int file_size; ///< filesize, not always right
41 unsigned int segments; ///< number of 512 byte segments
42 unsigned int audio_identifier; ///< 'MP3' on all files I have seen
43 unsigned int audio_br; ///< bitrate of audio channel (mp3)
44 unsigned int img_colorfmt; ///< frame colorfmt rgb 565/555
45 unsigned int img_bpp; ///< frame bits per pixel
46 unsigned int img_width;
47 unsigned int img_height;
48 unsigned int img_segment_size; ///< size of image segment
49 unsigned int video_fps;
50 unsigned int full_segment_size;
51
52} MTVDemuxContext;
53
54static int mtv_probe(AVProbeData *p)
55{
56 /* we need at least 57 bytes from the header
57 * to try parsing all required fields
58 */
59 if (p->buf_size < 57)
60 return 0;
61
62 /* Magic is 'AMV' */
63 if (*p->buf != 'A' || *(p->buf + 1) != 'M' || *(p->buf + 2) != 'V')
64 return 0;
65
66 /* Audio magic is always MP3 */
67 if (p->buf[43] != 'M' || p->buf[44] != 'P' || p->buf[45] != '3')
68 return 0;
69
70 /* Check for nonzero in bpp and (width|height) header fields */
71 if(!(p->buf[51] && AV_RL16(&p->buf[52]) | AV_RL16(&p->buf[54])))
72 return 0;
73
74 /* If width or height are 0 then imagesize header field should not */
75 if(!AV_RL16(&p->buf[52]) || !AV_RL16(&p->buf[54]))
76 {
77 if(!!AV_RL16(&p->buf[56]))
78 return AVPROBE_SCORE_EXTENSION;
79 else
80 return 0;
81 }
82
83 /* Image bpp is not an absolutely required
84 * field as we latter claim it should be 16
85 * no matter what. All samples in the wild
86 * are RGB565/555.
87 */
88 if(p->buf[51] != MTV_IMAGE_DEFAULT_BPP)
89 return AVPROBE_SCORE_EXTENSION / 2;
90
91 /* We had enough data to parse header values
92 * but we expect to be able to get 512 bytes
93 * of header to be sure.
94 */
95 if (p->buf_size < MTV_HEADER_SIZE)
96 return AVPROBE_SCORE_EXTENSION;
97
98 return AVPROBE_SCORE_MAX;
99}
100
101static int mtv_read_header(AVFormatContext *s)
102{
103 MTVDemuxContext *mtv = s->priv_data;
104 AVIOContext *pb = s->pb;
105 AVStream *st;
106 unsigned int audio_subsegments;
107
108 avio_skip(pb, 3);
109 mtv->file_size = avio_rl32(pb);
110 mtv->segments = avio_rl32(pb);
111 avio_skip(pb, 32);
112 mtv->audio_identifier = avio_rl24(pb);
113 mtv->audio_br = avio_rl16(pb);
114 mtv->img_colorfmt = avio_rl24(pb);
115 mtv->img_bpp = avio_r8(pb)>>3;
116 mtv->img_width = avio_rl16(pb);
117 mtv->img_height = avio_rl16(pb);
118 mtv->img_segment_size = avio_rl16(pb);
119
120 /* Assume 16bpp even if claimed otherwise.
121 * We know its going to be RGBG565/555 anyway
122 */
123 if (mtv->img_bpp != MTV_IMAGE_DEFAULT_BPP) {
124 av_log (s, AV_LOG_WARNING, "Header claims %dbpp (!= 16). Ignoring\n",
125 mtv->img_bpp);
126 mtv->img_bpp = MTV_IMAGE_DEFAULT_BPP;
127 }
128
129 /* Calculate width and height if missing from header */
130
131 if(!mtv->img_width && mtv->img_height)
132 mtv->img_width=mtv->img_segment_size / (mtv->img_bpp)
133 / mtv->img_height;
134
135 if(!mtv->img_height && mtv->img_width)
136 mtv->img_height=mtv->img_segment_size / (mtv->img_bpp)
137 / mtv->img_width;
138
139 if(!mtv->img_height || !mtv->img_width || !mtv->img_segment_size){
140 av_log(s, AV_LOG_ERROR, "width or height or segment_size is invalid and I cannot calculate them from other information\n");
141 return AVERROR(EINVAL);
142 }
143
144 avio_skip(pb, 4);
145 audio_subsegments = avio_rl16(pb);
146
147 if (audio_subsegments == 0) {
148 avpriv_request_sample(s, "MTV files without audio");
149 return AVERROR_PATCHWELCOME;
150 }
151
152 mtv->full_segment_size =
153 audio_subsegments * (MTV_AUDIO_PADDING_SIZE + MTV_ASUBCHUNK_DATA_SIZE) +
154 mtv->img_segment_size;
155 mtv->video_fps = (mtv->audio_br / 4) / audio_subsegments;
156
157 // FIXME Add sanity check here
158
159 // all systems go! init decoders
160
161 // video - raw rgb565
162
163 st = avformat_new_stream(s, NULL);
164 if(!st)
165 return AVERROR(ENOMEM);
166
167 avpriv_set_pts_info(st, 64, 1, mtv->video_fps);
168 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
169 st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
170 st->codec->pix_fmt = AV_PIX_FMT_RGB565BE;
171 st->codec->width = mtv->img_width;
172 st->codec->height = mtv->img_height;
173 st->codec->extradata = av_strdup("BottomUp");
174 st->codec->extradata_size = 9;
175
176 // audio - mp3
177
178 st = avformat_new_stream(s, NULL);
179 if(!st)
180 return AVERROR(ENOMEM);
181
182 avpriv_set_pts_info(st, 64, 1, MTV_AUDIO_SAMPLING_RATE);
183 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
184 st->codec->codec_id = AV_CODEC_ID_MP3;
185 st->codec->bit_rate = mtv->audio_br;
186 st->need_parsing = AVSTREAM_PARSE_FULL;
187
188 // Jump over header
189
190 if(avio_seek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE)
191 return AVERROR(EIO);
192
193 return 0;
194
195}
196
197static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt)
198{
199 MTVDemuxContext *mtv = s->priv_data;
200 AVIOContext *pb = s->pb;
201 int ret;
202
203 if((avio_tell(pb) - s->data_offset + mtv->img_segment_size) % mtv->full_segment_size)
204 {
205 avio_skip(pb, MTV_AUDIO_PADDING_SIZE);
206
207 ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE);
208 if(ret < 0)
209 return ret;
210
211 pkt->pos -= MTV_AUDIO_PADDING_SIZE;
212 pkt->stream_index = 1;
213
214 }else
215 {
216 ret = av_get_packet(pb, pkt, mtv->img_segment_size);
217 if(ret < 0)
218 return ret;
219
220 pkt->stream_index = 0;
221 }
222
223 return ret;
224}
225
226AVInputFormat ff_mtv_demuxer = {
227 .name = "mtv",
228 .long_name = NULL_IF_CONFIG_SMALL("MTV"),
229 .priv_data_size = sizeof(MTVDemuxContext),
230 .read_probe = mtv_probe,
231 .read_header = mtv_read_header,
232 .read_packet = mtv_read_packet,
233};