3 * Copyright (c) 2006 Reynaldo H. Verdejo Pinochet
5 * This file is part of FFmpeg.
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.
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.
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
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
37 typedef struct MTVDemuxContext {
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
51 uint8_t audio_packet_count;
55 static int mtv_probe(AVProbeData *p)
62 if(*(p->buf) != 'A' || *(p->buf+1) != 'M' || *(p->buf+2) != 'V')
65 return AVPROBE_SCORE_MAX;
68 static int mtv_read_header(AVFormatContext *s, AVFormatParameters *ap)
70 MTVDemuxContext *mtv = s->priv_data;
71 ByteIOContext *pb = &s->pb;
76 mtv->file_size = get_le32(pb);
77 mtv->segments = get_le32(pb);
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);
87 mtv->audio_subsegments = get_le16(pb);
88 mtv->video_fps = (mtv->audio_br / 4) / mtv->audio_subsegments;
90 /* FIXME Add sanity check here */
92 /* first packet is allways audio*/
94 mtv->audio_packet_count = 1;
96 /* all systems go! init decoders */
98 /* video - raw rgb565 */
100 st = av_new_stream(s, VIDEO_SID);
102 return AVERROR_NOMEM;
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->codec_tag = MKTAG('R', 'G', 'B', mtv->img_bpp);
108 st->codec->width = mtv->img_width;
109 st->codec->height = mtv->img_height;
110 st->codec->bits_per_sample = mtv->img_bpp;
111 st->codec->sample_rate = mtv->video_fps;
115 st = av_new_stream(s, AUDIO_SID);
117 return AVERROR_NOMEM;
119 av_set_pts_info(st, 64, 1, AUDIO_SAMPLING_RATE);
120 st->codec->codec_type = CODEC_TYPE_AUDIO;
121 st->codec->codec_id = CODEC_ID_MP3;
122 st->codec->bit_rate = mtv->audio_br;
125 /* Jump over header */
127 if(url_fseek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE)
134 static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt)
136 MTVDemuxContext *mtv = s->priv_data;
137 ByteIOContext *pb = &s->pb;
139 #ifndef WORDS_BIGENDIAN
145 if(mtv->audio_subsegments >= mtv->audio_packet_count)
147 url_fskip(pb, MTV_AUDIO_PADDING_SIZE);
149 ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE);
150 if(ret != MTV_ASUBCHUNK_DATA_SIZE)
153 mtv->audio_packet_count++;
154 pkt->stream_index = AUDIO_SID;
158 ret = av_get_packet(pb, pkt, mtv->img_segment_size);
159 if(ret != mtv->img_segment_size)
162 #ifndef WORDS_BIGENDIAN
164 /* pkt->data is GGGRRRR BBBBBGGG
165 * and we need RRRRRGGG GGGBBBBB
166 * for PIX_FMT_RGB565 so here we
167 * just swap bytes as they come
170 for(i=0;i<mtv->img_segment_size/2;i++)
171 *((uint16_t *)pkt->data+i) = bswap_16(*((uint16_t *)pkt->data+i));
173 mtv->audio_packet_count = 1;
174 pkt->stream_index = VIDEO_SID;
180 AVInputFormat mtv_demuxer = {
183 sizeof(MTVDemuxContext),