diff options
Diffstat (limited to 'ffmpeg/libavformat/flacenc.c')
| -rw-r--r-- | ffmpeg/libavformat/flacenc.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/ffmpeg/libavformat/flacenc.c b/ffmpeg/libavformat/flacenc.c new file mode 100644 index 0000000..b625278 --- /dev/null +++ b/ffmpeg/libavformat/flacenc.c @@ -0,0 +1,140 @@ +/* + * raw FLAC muxer + * Copyright (c) 2006-2009 Justin Ruggles + * + * 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 "libavcodec/flac.h" +#include "avformat.h" +#include "flacenc.h" +#include "vorbiscomment.h" +#include "libavcodec/bytestream.h" + + +static int flac_write_block_padding(AVIOContext *pb, unsigned int n_padding_bytes, + int last_block) +{ + avio_w8(pb, last_block ? 0x81 : 0x01); + avio_wb24(pb, n_padding_bytes); + while (n_padding_bytes > 0) { + avio_w8(pb, 0); + n_padding_bytes--; + } + return 0; +} + +static int flac_write_block_comment(AVIOContext *pb, AVDictionary **m, + int last_block, int bitexact) +{ + const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT; + unsigned int len, count; + uint8_t *p, *p0; + + ff_metadata_conv(m, ff_vorbiscomment_metadata_conv, NULL); + + len = ff_vorbiscomment_length(*m, vendor, &count); + p0 = av_malloc(len+4); + if (!p0) + return AVERROR(ENOMEM); + p = p0; + + bytestream_put_byte(&p, last_block ? 0x84 : 0x04); + bytestream_put_be24(&p, len); + ff_vorbiscomment_write(&p, m, vendor, count); + + avio_write(pb, p0, len+4); + av_freep(&p0); + p = NULL; + + return 0; +} + +static int flac_write_header(struct AVFormatContext *s) +{ + int ret; + AVCodecContext *codec = s->streams[0]->codec; + + if (s->nb_streams > 1) { + av_log(s, AV_LOG_ERROR, "only one stream is supported\n"); + return AVERROR(EINVAL); + } + if (codec->codec_id != AV_CODEC_ID_FLAC) { + av_log(s, AV_LOG_ERROR, "unsupported codec\n"); + return AVERROR(EINVAL); + } + + ret = ff_flac_write_header(s->pb, codec, 0); + if (ret) + return ret; + + ret = flac_write_block_comment(s->pb, &s->metadata, 0, + codec->flags & CODEC_FLAG_BITEXACT); + if (ret) + return ret; + + /* The command line flac encoder defaults to placing a seekpoint + * every 10s. So one might add padding to allow that later + * but there seems to be no simple way to get the duration here. + * So let's try the flac default of 8192 bytes */ + flac_write_block_padding(s->pb, 8192, 1); + + return ret; +} + +static int flac_write_trailer(struct AVFormatContext *s) +{ + AVIOContext *pb = s->pb; + uint8_t *streaminfo; + enum FLACExtradataFormat format; + int64_t file_size; + + if (!avpriv_flac_is_extradata_valid(s->streams[0]->codec, &format, &streaminfo)) + return -1; + + if (pb->seekable) { + /* rewrite the STREAMINFO header block data */ + file_size = avio_tell(pb); + avio_seek(pb, 8, SEEK_SET); + avio_write(pb, streaminfo, FLAC_STREAMINFO_SIZE); + avio_seek(pb, file_size, SEEK_SET); + avio_flush(pb); + } else { + av_log(s, AV_LOG_WARNING, "unable to rewrite FLAC header.\n"); + } + return 0; +} + +static int flac_write_packet(struct AVFormatContext *s, AVPacket *pkt) +{ + avio_write(s->pb, pkt->data, pkt->size); + avio_flush(s->pb); + return 0; +} + +AVOutputFormat ff_flac_muxer = { + .name = "flac", + .long_name = NULL_IF_CONFIG_SMALL("raw FLAC"), + .mime_type = "audio/x-flac", + .extensions = "flac", + .audio_codec = AV_CODEC_ID_FLAC, + .video_codec = AV_CODEC_ID_NONE, + .write_header = flac_write_header, + .write_packet = flac_write_packet, + .write_trailer = flac_write_trailer, + .flags = AVFMT_NOTIMESTAMPS, +}; |