yading@11: /* yading@11: * mtv demuxer yading@11: * Copyright (c) 2006 Reynaldo H. Verdejo Pinochet yading@11: * yading@11: * This file is part of FFmpeg. yading@11: * yading@11: * FFmpeg is free software; you can redistribute it and/or yading@11: * modify it under the terms of the GNU Lesser General Public yading@11: * License as published by the Free Software Foundation; either yading@11: * version 2.1 of the License, or (at your option) any later version. yading@11: * yading@11: * FFmpeg is distributed in the hope that it will be useful, yading@11: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@11: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@11: * Lesser General Public License for more details. yading@11: * yading@11: * You should have received a copy of the GNU Lesser General Public yading@11: * License along with FFmpeg; if not, write to the Free Software yading@11: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@11: */ yading@11: yading@11: /** yading@11: * @file yading@11: * MTV demuxer. yading@11: */ yading@11: yading@11: #include "libavutil/bswap.h" yading@11: #include "libavutil/intreadwrite.h" yading@11: #include "avformat.h" yading@11: #include "internal.h" yading@11: yading@11: #define MTV_ASUBCHUNK_DATA_SIZE 500 yading@11: #define MTV_HEADER_SIZE 512 yading@11: #define MTV_AUDIO_PADDING_SIZE 12 yading@11: #define AUDIO_SAMPLING_RATE 44100 yading@11: yading@11: typedef struct MTVDemuxContext { yading@11: yading@11: unsigned int file_size; ///< filesize, not always right yading@11: unsigned int segments; ///< number of 512 byte segments yading@11: unsigned int audio_identifier; ///< 'MP3' on all files I have seen yading@11: unsigned int audio_br; ///< bitrate of audio channel (mp3) yading@11: unsigned int img_colorfmt; ///< frame colorfmt rgb 565/555 yading@11: unsigned int img_bpp; ///< frame bits per pixel yading@11: unsigned int img_width; // yading@11: unsigned int img_height; // yading@11: unsigned int img_segment_size; ///< size of image segment yading@11: unsigned int video_fps; // yading@11: unsigned int full_segment_size; yading@11: yading@11: } MTVDemuxContext; yading@11: yading@11: static int mtv_probe(AVProbeData *p) yading@11: { yading@11: /* Magic is 'AMV' */ yading@11: if (*p->buf != 'A' || *(p->buf + 1) != 'M' || *(p->buf + 2) != 'V') yading@11: return 0; yading@11: yading@11: /* Check for nonzero in bpp and (width|height) header fields */ yading@11: if(p->buf_size < 57 || !(p->buf[51] && AV_RL16(&p->buf[52]) | AV_RL16(&p->buf[54]))) yading@11: return 0; yading@11: yading@11: /* If width or height are 0 then imagesize header field should not */ yading@11: if(!AV_RL16(&p->buf[52]) || !AV_RL16(&p->buf[54])) yading@11: { yading@11: if(!!AV_RL16(&p->buf[56])) yading@11: return AVPROBE_SCORE_MAX/2; yading@11: else yading@11: return 0; yading@11: } yading@11: yading@11: if(p->buf[51] != 16) yading@11: return AVPROBE_SCORE_MAX/4; // But we are going to assume 16bpp anyway .. yading@11: yading@11: return AVPROBE_SCORE_MAX; yading@11: } yading@11: yading@11: static int mtv_read_header(AVFormatContext *s) yading@11: { yading@11: MTVDemuxContext *mtv = s->priv_data; yading@11: AVIOContext *pb = s->pb; yading@11: AVStream *st; yading@11: unsigned int audio_subsegments; yading@11: yading@11: avio_skip(pb, 3); yading@11: mtv->file_size = avio_rl32(pb); yading@11: mtv->segments = avio_rl32(pb); yading@11: avio_skip(pb, 32); yading@11: mtv->audio_identifier = avio_rl24(pb); yading@11: mtv->audio_br = avio_rl16(pb); yading@11: mtv->img_colorfmt = avio_rl24(pb); yading@11: mtv->img_bpp = avio_r8(pb); yading@11: mtv->img_width = avio_rl16(pb); yading@11: mtv->img_height = avio_rl16(pb); yading@11: mtv->img_segment_size = avio_rl16(pb); yading@11: yading@11: /* Calculate width and height if missing from header */ yading@11: yading@11: if(mtv->img_bpp>>3){ yading@11: if(!mtv->img_width && mtv->img_height) yading@11: mtv->img_width=mtv->img_segment_size / (mtv->img_bpp>>3) yading@11: / mtv->img_height; yading@11: yading@11: if(!mtv->img_height && mtv->img_width) yading@11: mtv->img_height=mtv->img_segment_size / (mtv->img_bpp>>3) yading@11: / mtv->img_width; yading@11: } yading@11: if(!mtv->img_height || !mtv->img_width){ yading@11: av_log(s, AV_LOG_ERROR, "width or height is invalid and I cannot calculate them from other information\n"); yading@11: return AVERROR(EINVAL); yading@11: } yading@11: yading@11: avio_skip(pb, 4); yading@11: audio_subsegments = avio_rl16(pb); yading@11: yading@11: if (audio_subsegments == 0) { yading@11: avpriv_request_sample(s, "MTV files without audio"); yading@11: return AVERROR_PATCHWELCOME; yading@11: } yading@11: yading@11: mtv->full_segment_size = yading@11: audio_subsegments * (MTV_AUDIO_PADDING_SIZE + MTV_ASUBCHUNK_DATA_SIZE) + yading@11: mtv->img_segment_size; yading@11: mtv->video_fps = (mtv->audio_br / 4) / audio_subsegments; yading@11: yading@11: // FIXME Add sanity check here yading@11: yading@11: // all systems go! init decoders yading@11: yading@11: // video - raw rgb565 yading@11: yading@11: st = avformat_new_stream(s, NULL); yading@11: if(!st) yading@11: return AVERROR(ENOMEM); yading@11: yading@11: avpriv_set_pts_info(st, 64, 1, mtv->video_fps); yading@11: st->codec->codec_type = AVMEDIA_TYPE_VIDEO; yading@11: st->codec->codec_id = AV_CODEC_ID_RAWVIDEO; yading@11: st->codec->pix_fmt = AV_PIX_FMT_RGB565BE; yading@11: st->codec->width = mtv->img_width; yading@11: st->codec->height = mtv->img_height; yading@11: st->codec->sample_rate = mtv->video_fps; yading@11: st->codec->extradata = av_strdup("BottomUp"); yading@11: st->codec->extradata_size = 9; yading@11: yading@11: // audio - mp3 yading@11: yading@11: st = avformat_new_stream(s, NULL); yading@11: if(!st) yading@11: return AVERROR(ENOMEM); yading@11: yading@11: avpriv_set_pts_info(st, 64, 1, AUDIO_SAMPLING_RATE); yading@11: st->codec->codec_type = AVMEDIA_TYPE_AUDIO; yading@11: st->codec->codec_id = AV_CODEC_ID_MP3; yading@11: st->codec->bit_rate = mtv->audio_br; yading@11: st->need_parsing = AVSTREAM_PARSE_FULL; yading@11: yading@11: // Jump over header yading@11: yading@11: if(avio_seek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE) yading@11: return AVERROR(EIO); yading@11: yading@11: return 0; yading@11: yading@11: } yading@11: yading@11: static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt) yading@11: { yading@11: MTVDemuxContext *mtv = s->priv_data; yading@11: AVIOContext *pb = s->pb; yading@11: int ret; yading@11: yading@11: if((avio_tell(pb) - s->data_offset + mtv->img_segment_size) % mtv->full_segment_size) yading@11: { yading@11: avio_skip(pb, MTV_AUDIO_PADDING_SIZE); yading@11: yading@11: ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE); yading@11: if(ret < 0) yading@11: return ret; yading@11: yading@11: pkt->pos -= MTV_AUDIO_PADDING_SIZE; yading@11: pkt->stream_index = 1; yading@11: yading@11: }else yading@11: { yading@11: ret = av_get_packet(pb, pkt, mtv->img_segment_size); yading@11: if(ret < 0) yading@11: return ret; yading@11: yading@11: pkt->stream_index = 0; yading@11: } yading@11: yading@11: return ret; yading@11: } yading@11: yading@11: AVInputFormat ff_mtv_demuxer = { yading@11: .name = "mtv", yading@11: .long_name = NULL_IF_CONFIG_SMALL("MTV"), yading@11: .priv_data_size = sizeof(MTVDemuxContext), yading@11: .read_probe = mtv_probe, yading@11: .read_header = mtv_read_header, yading@11: .read_packet = mtv_read_packet, yading@11: };