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
27 #include "libavutil/bswap.h"
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 full_segment_size;
53 static int mtv_probe(AVProbeData *p)
57 if(*(p->buf) != 'A' || *(p->buf+1) != 'M' || *(p->buf+2) != 'V')
60 return AVPROBE_SCORE_MAX;
63 static int mtv_read_header(AVFormatContext *s, AVFormatParameters *ap)
65 MTVDemuxContext *mtv = s->priv_data;
66 ByteIOContext *pb = s->pb;
68 unsigned int audio_subsegments;
72 mtv->file_size = get_le32(pb);
73 mtv->segments = get_le32(pb);
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);
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;
89 /* FIXME Add sanity check here */
91 /* all systems go! init decoders */
93 /* video - raw rgb565 */
95 st = av_new_stream(s, VIDEO_SID);
97 return AVERROR(ENOMEM);
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;
102 st->codec->codec_tag = MKTAG('R', 'G', 'B', mtv->img_bpp);
103 st->codec->width = mtv->img_width;
104 st->codec->height = mtv->img_height;
105 st->codec->bits_per_coded_sample = mtv->img_bpp;
106 st->codec->sample_rate = mtv->video_fps;
110 st = av_new_stream(s, AUDIO_SID);
112 return AVERROR(ENOMEM);
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;
118 st->need_parsing = AVSTREAM_PARSE_FULL;
120 /* Jump over header */
122 if(url_fseek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE)
129 static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt)
131 MTVDemuxContext *mtv = s->priv_data;
132 ByteIOContext *pb = s->pb;
134 #ifndef WORDS_BIGENDIAN
140 if((url_ftell(pb) - s->data_offset + mtv->img_segment_size) % mtv->full_segment_size)
142 url_fskip(pb, MTV_AUDIO_PADDING_SIZE);
144 ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE);
145 if(ret != MTV_ASUBCHUNK_DATA_SIZE)
148 pkt->pos -= MTV_AUDIO_PADDING_SIZE;
149 pkt->stream_index = AUDIO_SID;
153 ret = av_get_packet(pb, pkt, mtv->img_segment_size);
154 if(ret != mtv->img_segment_size)
157 #ifndef WORDS_BIGENDIAN
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
165 for(i=0;i<mtv->img_segment_size/2;i++)
166 *((uint16_t *)pkt->data+i) = bswap_16(*((uint16_t *)pkt->data+i));
168 pkt->stream_index = VIDEO_SID;
174 AVInputFormat mtv_demuxer = {
176 NULL_IF_CONFIG_SMALL("MTV format"),
177 sizeof(MTVDemuxContext),