mirror of
				https://github.com/nyanmisaka/ffmpeg-rockchip.git
				synced 2025-11-01 04:53:04 +08:00 
			
		
		
		
	
		
			
				
	
	
		
			95 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			95 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * CRYO APC audio format demuxer
 | |
|  * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
 | |
|  *
 | |
|  * 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
 | |
|  */
 | |
| 
 | |
| #include <string.h>
 | |
| 
 | |
| #include "libavutil/channel_layout.h"
 | |
| #include "avformat.h"
 | |
| #include "internal.h"
 | |
| 
 | |
| static int apc_probe(AVProbeData *p)
 | |
| {
 | |
|     if (!strncmp(p->buf, "CRYO_APC", 8))
 | |
|         return AVPROBE_SCORE_MAX;
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| static int apc_read_header(AVFormatContext *s)
 | |
| {
 | |
|     AVIOContext *pb = s->pb;
 | |
|     AVStream *st;
 | |
| 
 | |
|     avio_rl32(pb); /* CRYO */
 | |
|     avio_rl32(pb); /* _APC */
 | |
|     avio_rl32(pb); /* 1.20 */
 | |
| 
 | |
|     st = avformat_new_stream(s, NULL);
 | |
|     if (!st)
 | |
|         return AVERROR(ENOMEM);
 | |
| 
 | |
|     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
 | |
|     st->codec->codec_id = AV_CODEC_ID_ADPCM_IMA_APC;
 | |
| 
 | |
|     avio_rl32(pb); /* number of samples */
 | |
|     st->codec->sample_rate = avio_rl32(pb);
 | |
| 
 | |
|     if (ff_alloc_extradata(st->codec, 2 * 4))
 | |
|         return AVERROR(ENOMEM);
 | |
| 
 | |
|     /* initial predictor values for adpcm decoder */
 | |
|     avio_read(pb, st->codec->extradata, 2 * 4);
 | |
| 
 | |
|     if (avio_rl32(pb)) {
 | |
|         st->codec->channels       = 2;
 | |
|         st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
 | |
|     } else {
 | |
|         st->codec->channels       = 1;
 | |
|         st->codec->channel_layout = AV_CH_LAYOUT_MONO;
 | |
|     }
 | |
| 
 | |
|     st->codec->bits_per_coded_sample = 4;
 | |
|     st->codec->bit_rate = st->codec->bits_per_coded_sample * st->codec->channels
 | |
|                           * st->codec->sample_rate;
 | |
|     st->codec->block_align = 1;
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| #define MAX_READ_SIZE 4096
 | |
| 
 | |
| static int apc_read_packet(AVFormatContext *s, AVPacket *pkt)
 | |
| {
 | |
|     if (av_get_packet(s->pb, pkt, MAX_READ_SIZE) <= 0)
 | |
|         return AVERROR(EIO);
 | |
|     pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
 | |
|     pkt->stream_index = 0;
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| AVInputFormat ff_apc_demuxer = {
 | |
|     .name           = "apc",
 | |
|     .long_name      = NULL_IF_CONFIG_SMALL("CRYO APC"),
 | |
|     .read_probe     = apc_probe,
 | |
|     .read_header    = apc_read_header,
 | |
|     .read_packet    = apc_read_packet,
 | |
| };
 | 
