/* * G.729 bit format muxer and demuxer * Copyright (c) 2007-2008 Vladimir Voroshilov * * 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 "avformat.h" #include "internal.h" #include "libavcodec/get_bits.h" #include "libavcodec/put_bits.h" #define MAX_FRAME_SIZE 10 #define SYNC_WORD 0x6b21 #define BIT_0 0x7f #define BIT_1 0x81 static int probe(AVProbeData *p) { int i, j; if(p->buf_size < 0x40) return 0; for(i=0; i+3<p->buf_size && i< 10*0x50; ){ if(AV_RL16(&p->buf[0]) != SYNC_WORD) return 0; j=AV_RL16(&p->buf[2]); if(j!=0x40 && j!=0x50) return 0; i+=j; } return AVPROBE_SCORE_MAX/2; } static int read_header(AVFormatContext *s) { AVStream* st; 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_G729; st->codec->sample_rate=8000; st->codec->block_align = 16; st->codec->channels=1; avpriv_set_pts_info(st, 64, 1, 100); return 0; } static int read_packet(AVFormatContext *s, AVPacket *pkt) { AVIOContext *pb = s->pb; PutBitContext pbo; uint16_t buf[8 * MAX_FRAME_SIZE + 2]; int packet_size; uint16_t* src=buf; int i, j, ret; int64_t pos= avio_tell(pb); if(url_feof(pb)) return AVERROR_EOF; avio_rl16(pb); // sync word packet_size = avio_rl16(pb) / 8; if(packet_size > MAX_FRAME_SIZE) return AVERROR_INVALIDDATA; ret = avio_read(pb, (uint8_t*)buf, (8 * packet_size) * sizeof(uint16_t)); if(ret<0) return ret; if(ret != 8 * packet_size * sizeof(uint16_t)) return AVERROR(EIO); if (av_new_packet(pkt, packet_size) < 0) return AVERROR(ENOMEM); init_put_bits(&pbo, pkt->data, packet_size); for(j=0; j < packet_size; j++) for(i=0; i<8;i++) put_bits(&pbo,1, AV_RL16(src++) == BIT_1 ? 1 : 0); flush_put_bits(&pbo); pkt->duration=1; pkt->pos = pos; return 0; } AVInputFormat ff_bit_demuxer = { .name = "bit", .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"), .read_probe = probe, .read_header = read_header, .read_packet = read_packet, .extensions = "bit", }; #if CONFIG_MUXERS static int write_header(AVFormatContext *s) { AVCodecContext *enc = s->streams[0]->codec; enc->codec_id = AV_CODEC_ID_G729; enc->channels = 1; enc->bits_per_coded_sample = 16; enc->block_align = (enc->bits_per_coded_sample * enc->channels) >> 3; return 0; } static int write_packet(AVFormatContext *s, AVPacket *pkt) { AVIOContext *pb = s->pb; GetBitContext gb; int i; avio_wl16(pb, SYNC_WORD); avio_wl16(pb, 8 * 10); init_get_bits(&gb, pkt->data, 8*10); for(i=0; i< 8 * 10; i++) avio_wl16(pb, get_bits1(&gb) ? BIT_1 : BIT_0); avio_flush(pb); return 0; } AVOutputFormat ff_bit_muxer = { .name = "bit", .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"), .mime_type = "audio/bit", .extensions = "bit", .audio_codec = AV_CODEC_ID_G729, .video_codec = AV_CODEC_ID_NONE, .write_header = write_header, .write_packet = write_packet, }; #endif