From a2b251a05e6f87bca826269d4baa5b8da7aeb430 Mon Sep 17 00:00:00 2001 From: Martin Storsjö Date: Sun, 17 Jun 2012 15:54:31 +0300 Subject: Implement the iLBC storage file format MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Martin Storsjö --- libavformat/ilbc.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 141 insertions(+) create mode 100644 libavformat/ilbc.c (limited to 'libavformat/ilbc.c') diff --git a/libavformat/ilbc.c b/libavformat/ilbc.c new file mode 100644 index 0000000000..33aed77163 --- /dev/null +++ b/libavformat/ilbc.c @@ -0,0 +1,141 @@ +/* + * iLBC storage file format + * Copyright (c) 2012 Martin Storsjo + * + * This file is part of Libav. + * + * Libav 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. + * + * Libav 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 Libav; 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" + +static const char mode20_header[] = "#!iLBC20\n"; +static const char mode30_header[] = "#!iLBC30\n"; + +static int ilbc_write_header(AVFormatContext *s) +{ + AVIOContext *pb = s->pb; + AVCodecContext *enc; + + if (s->nb_streams != 1) { + av_log(s, AV_LOG_ERROR, "Unsupported number of streams\n"); + return AVERROR(EINVAL); + } + enc = s->streams[0]->codec; + + if (enc->codec_id != CODEC_ID_ILBC) { + av_log(s, AV_LOG_ERROR, "Unsupported codec\n"); + return AVERROR(EINVAL); + } + + if (enc->block_align == 50) { + avio_write(pb, mode30_header, sizeof(mode30_header) - 1); + } else if (enc->block_align == 38) { + avio_write(pb, mode20_header, sizeof(mode20_header) - 1); + } else { + av_log(s, AV_LOG_ERROR, "Unsupported mode\n"); + return AVERROR(EINVAL); + } + avio_flush(pb); + return 0; +} + +static int ilbc_write_packet(AVFormatContext *s, AVPacket *pkt) +{ + avio_write(s->pb, pkt->data, pkt->size); + avio_flush(s->pb); + return 0; +} + +static int ilbc_probe(AVProbeData *p) +{ + // Only check for "#!iLBC" which matches both formats + if (!memcmp(p->buf, mode20_header, 6)) + return AVPROBE_SCORE_MAX; + else + return 0; +} + +static int ilbc_read_header(AVFormatContext *s) +{ + AVIOContext *pb = s->pb; + AVStream *st; + uint8_t header[9]; + + avio_read(pb, header, 9); + + st = avformat_new_stream(s, NULL); + if (!st) + return AVERROR(ENOMEM); + st->codec->codec_id = CODEC_ID_ILBC; + st->codec->sample_rate = 8000; + st->codec->channels = 1; + st->codec->codec_type = AVMEDIA_TYPE_AUDIO; + st->start_time = 0; + avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate); + if (!memcmp(header, mode20_header, sizeof(mode20_header) - 1)) { + st->codec->block_align = 38; + st->codec->bit_rate = 15200; + } else if (!memcmp(header, mode30_header, sizeof(mode30_header) - 1)) { + st->codec->block_align = 50; + st->codec->bit_rate = 13333; + } else { + av_log(s, AV_LOG_ERROR, "Unrecognized iLBC file header\n"); + return AVERROR_INVALIDDATA; + } + + return 0; +} + +static int ilbc_read_packet(AVFormatContext *s, + AVPacket *pkt) +{ + AVCodecContext *enc = s->streams[0]->codec; + int ret; + + if ((ret = av_new_packet(pkt, enc->block_align)) < 0) + return ret; + + pkt->stream_index = 0; + pkt->pos = avio_tell(s->pb); + pkt->duration = enc->block_align == 38 ? 160 : 240; + if ((ret = avio_read(s->pb, pkt->data, enc->block_align)) != enc->block_align) { + av_free_packet(pkt); + return ret < 0 ? ret : AVERROR(EIO); + } + + return 0; +} + +AVInputFormat ff_ilbc_demuxer = { + .name = "ilbc", + .long_name = NULL_IF_CONFIG_SMALL("iLBC storage file format"), + .read_probe = ilbc_probe, + .read_header = ilbc_read_header, + .read_packet = ilbc_read_packet, + .flags = AVFMT_GENERIC_INDEX, +}; + +AVOutputFormat ff_ilbc_muxer = { + .name = "ilbc", + .long_name = NULL_IF_CONFIG_SMALL("iLBC storage file format"), + .mime_type = "audio/iLBC", + .extensions = "lbc", + .audio_codec = CODEC_ID_ILBC, + .write_header = ilbc_write_header, + .write_packet = ilbc_write_packet, + .flags = AVFMT_NOTIMESTAMPS, +}; -- cgit v1.2.3