FFmpeg: libavformat/rsoenc.c Source File

00001 /*
00002  * RSO muxer
00003  * Copyright (c) 2001 Fabrice Bellard (original AU code)
00004  * Copyright (c) 2010 Rafael Carre
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00023 #include "avformat.h"
00024 #include "internal.h"
00025 #include "riff.h"
00026 #include "rso.h"
00027 
00028 static int rso_write_header(AVFormatContext *s)
00029 {
00030     AVIOContext  *pb  = s->pb;
00031     AVCodecContext *enc = s->streams[0]->codec;
00032 
00033     if (!enc->codec_tag)
00034         return AVERROR_INVALIDDATA;
00035 
00036     if (enc->channels != 1) {
00037         av_log(s, AV_LOG_ERROR, "RSO only supports mono\n");
00038         return AVERROR_INVALIDDATA;
00039     }
00040 
00041     if (!s->pb->seekable) {
00042         av_log(s, AV_LOG_ERROR, "muxer does not support non seekable output\n");
00043         return AVERROR_INVALIDDATA;
00044     }
00045 
00046     /* XXX: find legal sample rates (if any) */
00047     if (enc->sample_rate >= 1u<<16) {
00048         av_log(s, AV_LOG_ERROR, "Sample rate must be < 65536\n");
00049         return AVERROR_INVALIDDATA;
00050     }
00051 
00052     if (enc->codec_id == AV_CODEC_ID_ADPCM_IMA_WAV) {
00053         av_log(s, AV_LOG_ERROR, "ADPCM in RSO not implemented\n");
00054         return AVERROR_PATCHWELCOME;
00055     }
00056 
00057     /* format header */
00058     avio_wb16(pb, enc->codec_tag);   /* codec ID */
00059     avio_wb16(pb, 0);                /* data size, will be written at EOF */
00060     avio_wb16(pb, enc->sample_rate);
00061     avio_wb16(pb, 0x0000);           /* play mode ? (0x0000 = don't loop) */
00062 
00063     avio_flush(pb);
00064 
00065     return 0;
00066 }
00067 
00068 static int rso_write_packet(AVFormatContext *s, AVPacket *pkt)
00069 {
00070     avio_write(s->pb, pkt->data, pkt->size);
00071     return 0;
00072 }
00073 
00074 static int rso_write_trailer(AVFormatContext *s)
00075 {
00076     AVIOContext *pb = s->pb;
00077     int64_t file_size;
00078     uint16_t coded_file_size;
00079 
00080     file_size = avio_tell(pb);
00081 
00082     if (file_size < 0)
00083         return file_size;
00084 
00085     if (file_size > 0xffff + RSO_HEADER_SIZE) {
00086         av_log(s, AV_LOG_WARNING,
00087                "Output file is too big (%"PRId64" bytes >= 64kB)\n", file_size);
00088         coded_file_size = 0xffff;
00089     } else {
00090         coded_file_size = file_size - RSO_HEADER_SIZE;
00091     }
00092 
00093     /* update file size */
00094     avio_seek(pb, 2, SEEK_SET);
00095     avio_wb16(pb, coded_file_size);
00096     avio_seek(pb, file_size, SEEK_SET);
00097 
00098     return 0;
00099 }
00100 
00101 AVOutputFormat ff_rso_muxer = {
00102     .name           =   "rso",
00103     .long_name      =   NULL_IF_CONFIG_SMALL("Lego Mindstorms RSO"),
00104     .extensions     =   "rso",
00105     .audio_codec    =   AV_CODEC_ID_PCM_U8,
00106     .video_codec    =   AV_CODEC_ID_NONE,
00107     .write_header   =   rso_write_header,
00108     .write_packet   =   rso_write_packet,
00109     .write_trailer  =   rso_write_trailer,
00110     .codec_tag      =   (const AVCodecTag* const []){ff_codec_rso_tags, 0},
00111 };