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* Copyright (c) 2006 Reynaldo H. Verdejo Pinochet
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* This file is part of FFmpeg.
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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#define MTV_ASUBCHUNK_DATA_SIZE 500
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#define MTV_HEADER_SIZE 512
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#define MTV_AUDIO_PADDING_SIZE 12
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#define AUDIO_SAMPLING_RATE 44100
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typedef struct MTVDemuxContext {
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unsigned int file_size; ///< filesize, not always right
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unsigned int segments; ///< number of 512 byte segments
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unsigned int audio_identifier; ///< 'MP3' on all files I have seen
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unsigned int audio_br; ///< bitrate of audio chanel (mp3)
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unsigned int img_colorfmt; ///< frame colorfmt rgb 565/555
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unsigned int img_bpp; ///< frame bits per pixel
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unsigned int img_width; //
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unsigned int img_height; //
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unsigned int img_segment_size; ///< size of image segment
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unsigned int video_fps; //
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unsigned int audio_subsegments; ///< audio subsegments on one segment
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uint8_t audio_packet_count;
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static int mtv_probe(AVProbeData *p)
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if(*(p->buf) != 'A' || *(p->buf+1) != 'M' || *(p->buf+2) != 'V')
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return AVPROBE_SCORE_MAX;
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static int mtv_read_header(AVFormatContext *s, AVFormatParameters *ap)
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MTVDemuxContext *mtv = s->priv_data;
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ByteIOContext *pb = &s->pb;
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mtv->file_size = get_le32(pb);
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mtv->segments = get_le32(pb);
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mtv->audio_identifier = get_le24(pb);
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mtv->audio_br = get_le16(pb);
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mtv->img_colorfmt = get_le24(pb);
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mtv->img_bpp = get_byte(pb);
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mtv->img_width = get_le16(pb);
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mtv->img_height = get_le16(pb);
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mtv->img_segment_size = get_le16(pb);
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mtv->audio_subsegments = get_le16(pb);
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mtv->video_fps = (mtv->audio_br / 4) / mtv->audio_subsegments;
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/* FIXME Add sanity check here */
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/* first packet is allways audio*/
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mtv->audio_packet_count = 1;
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/* all systems go! init decoders */
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/* video - raw rgb565 */
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st = av_new_stream(s, VIDEO_SID);
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return AVERROR_NOMEM;
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av_set_pts_info(st, 64, 1, mtv->video_fps);
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st->codec->codec_type = CODEC_TYPE_VIDEO;
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st->codec->codec_id = CODEC_ID_RAWVIDEO;
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st->codec->width = mtv->img_width;
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st->codec->height = mtv->img_height;
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st->codec->bits_per_sample = mtv->img_bpp;
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st->codec->sample_rate = mtv->video_fps;
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st = av_new_stream(s, AUDIO_SID);
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return AVERROR_NOMEM;
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av_set_pts_info(st, 64, 1, AUDIO_SAMPLING_RATE);
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st->codec->codec_type = CODEC_TYPE_AUDIO;
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st->codec->codec_id = CODEC_ID_MP3;
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st->codec->bit_rate = mtv->audio_br;
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/* Jump over header */
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if(url_fseek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE)
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static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt)
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MTVDemuxContext *mtv = s->priv_data;
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ByteIOContext *pb = &s->pb;
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#ifndef WORDS_BIGENDIAN
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if(mtv->audio_subsegments >= mtv->audio_packet_count)
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url_fskip(pb, MTV_AUDIO_PADDING_SIZE);
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ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE);
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if(ret != MTV_ASUBCHUNK_DATA_SIZE)
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mtv->audio_packet_count++;
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pkt->stream_index = AUDIO_SID;
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ret = av_get_packet(pb, pkt, mtv->img_segment_size);
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if(ret != mtv->img_segment_size)
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#ifndef WORDS_BIGENDIAN
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/* pkt->data is GGGRRRR BBBBBGGG
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* and we need RRRRRGGG GGGBBBBB
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* for PIX_FMT_RGB565 so here we
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* just swap bytes as they come
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for(i=0;i<mtv->img_segment_size/2;i++)
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*((uint16_t *)pkt->data+i) = bswap_16(*((uint16_t *)pkt->data+i));
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mtv->audio_packet_count = 1;
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pkt->stream_index = VIDEO_SID;
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AVInputFormat mtv_demuxer = {
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sizeof(MTVDemuxContext),