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