libavformat/rsodec.c
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00001 /*
00002  * RSO demuxer
00003  * Copyright (c) 2001 Fabrice Bellard (original AU code)
00004  * Copyright (c) 2010 Rafael Carre
00005  *
00006  * This file is part of Libav.
00007  *
00008  * Libav is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * Libav is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with Libav; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00023 #include "libavutil/intreadwrite.h"
00024 #include "avformat.h"
00025 #include "internal.h"
00026 #include "pcm.h"
00027 #include "riff.h"
00028 #include "rso.h"
00029 
00030 static int rso_read_header(AVFormatContext *s, AVFormatParameters *ap)
00031 {
00032     AVIOContext *pb = s->pb;
00033     int id, rate, bps;
00034     unsigned int size;
00035     enum CodecID codec;
00036     AVStream *st;
00037 
00038     id   = avio_rb16(pb);
00039     size = avio_rb16(pb);
00040     rate = avio_rb16(pb);
00041     avio_rb16(pb);   /* play mode ? (0x0000 = don't loop) */
00042 
00043     codec = ff_codec_get_id(ff_codec_rso_tags, id);
00044 
00045     if (codec == CODEC_ID_ADPCM_IMA_WAV) {
00046         av_log(s, AV_LOG_ERROR, "ADPCM in RSO not implemented\n");
00047         return AVERROR_PATCHWELCOME;
00048     }
00049 
00050     bps = av_get_bits_per_sample(codec);
00051     if (!bps) {
00052         av_log_ask_for_sample(s, "could not determine bits per sample\n");
00053         return AVERROR_INVALIDDATA;
00054     }
00055 
00056     /* now we are ready: build format streams */
00057     st = avformat_new_stream(s, NULL);
00058     if (!st)
00059         return AVERROR(ENOMEM);
00060 
00061     st->duration            = (size * 8) / bps;
00062     st->codec->codec_type   = AVMEDIA_TYPE_AUDIO;
00063     st->codec->codec_tag    = id;
00064     st->codec->codec_id     = codec;
00065     st->codec->channels     = 1;
00066     st->codec->sample_rate  = rate;
00067 
00068     avpriv_set_pts_info(st, 64, 1, rate);
00069 
00070     return 0;
00071 }
00072 
00073 #define BLOCK_SIZE 1024 /* in samples */
00074 
00075 static int rso_read_packet(AVFormatContext *s, AVPacket *pkt)
00076 {
00077     int bps = av_get_bits_per_sample(s->streams[0]->codec->codec_id);
00078     int ret = av_get_packet(s->pb, pkt, BLOCK_SIZE * bps >> 3);
00079 
00080     if (ret < 0)
00081         return ret;
00082 
00083     pkt->stream_index = 0;
00084 
00085     /* note: we need to modify the packet size here to handle the last packet */
00086     pkt->size = ret;
00087 
00088     return 0;
00089 }
00090 
00091 AVInputFormat ff_rso_demuxer = {
00092     .name           =   "rso",
00093     .long_name      =   NULL_IF_CONFIG_SMALL("Lego Mindstorms RSO format"),
00094     .extensions     =   "rso",
00095     .read_header    =   rso_read_header,
00096     .read_packet    =   rso_read_packet,
00097     .read_seek      =   pcm_read_seek,
00098     .codec_tag      =   (const AVCodecTag* const []){ff_codec_rso_tags, 0},
00099 };