3 * Copyright (c) 2006-2009 Justin Ruggles
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/opt.h"
23 #include "libavcodec/flac.h"
25 #include "avio_internal.h"
27 #include "vorbiscomment.h"
28 #include "libavcodec/bytestream.h"
31 typedef struct FlacMuxerContext {
36 static int flac_write_block_padding(AVIOContext *pb, unsigned int n_padding_bytes,
39 avio_w8(pb, last_block ? 0x81 : 0x01);
40 avio_wb24(pb, n_padding_bytes);
41 ffio_fill(pb, 0, n_padding_bytes);
45 static int flac_write_block_comment(AVIOContext *pb, AVDictionary **m,
46 int last_block, int bitexact)
48 const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT;
49 unsigned int len, count;
52 ff_metadata_conv(m, ff_vorbiscomment_metadata_conv, NULL);
54 len = ff_vorbiscomment_length(*m, vendor, &count);
55 p0 = av_malloc(len+4);
57 return AVERROR(ENOMEM);
60 bytestream_put_byte(&p, last_block ? 0x84 : 0x04);
61 bytestream_put_be24(&p, len);
62 ff_vorbiscomment_write(&p, m, vendor, count);
64 avio_write(pb, p0, len+4);
71 static int flac_write_header(struct AVFormatContext *s)
74 int padding = s->metadata_header_padding;
75 AVCodecContext *codec = s->streams[0]->codec;
76 FlacMuxerContext *c = s->priv_data;
81 if (s->nb_streams > 1) {
82 av_log(s, AV_LOG_ERROR, "only one stream is supported\n");
83 return AVERROR(EINVAL);
85 if (codec->codec_id != AV_CODEC_ID_FLAC) {
86 av_log(s, AV_LOG_ERROR, "unsupported codec\n");
87 return AVERROR(EINVAL);
92 /* The FLAC specification states that 24 bits are used to represent the
93 * size of a metadata block so we must clip this value to 2^24-1. */
94 padding = av_clip_c(padding, 0, 16777215);
96 ret = ff_flac_write_header(s->pb, codec, 0);
100 ret = flac_write_block_comment(s->pb, &s->metadata, !padding,
101 codec->flags & CODEC_FLAG_BITEXACT);
105 /* The command line flac encoder defaults to placing a seekpoint
106 * every 10s. So one might add padding to allow that later
107 * but there seems to be no simple way to get the duration here.
108 * So just add the amount requested by the user. */
110 flac_write_block_padding(s->pb, padding, 1);
115 static int flac_write_trailer(struct AVFormatContext *s)
117 AVIOContext *pb = s->pb;
119 enum FLACExtradataFormat format;
121 FlacMuxerContext *c = s->priv_data;
123 if (!c->write_header)
126 if (!avpriv_flac_is_extradata_valid(s->streams[0]->codec, &format, &streaminfo))
130 /* rewrite the STREAMINFO header block data */
131 file_size = avio_tell(pb);
132 avio_seek(pb, 8, SEEK_SET);
133 avio_write(pb, streaminfo, FLAC_STREAMINFO_SIZE);
134 avio_seek(pb, file_size, SEEK_SET);
137 av_log(s, AV_LOG_WARNING, "unable to rewrite FLAC header.\n");
142 static int flac_write_packet(struct AVFormatContext *s, AVPacket *pkt)
144 avio_write(s->pb, pkt->data, pkt->size);
148 static const AVOption flacenc_options[] = {
149 { "write_header", "Write the file header", offsetof(FlacMuxerContext, write_header), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
153 static const AVClass flac_muxer_class = {
154 .class_name = "flac muxer",
155 .item_name = av_default_item_name,
156 .option = flacenc_options,
157 .version = LIBAVUTIL_VERSION_INT,
160 AVOutputFormat ff_flac_muxer = {
162 .long_name = NULL_IF_CONFIG_SMALL("raw FLAC"),
163 .priv_data_size = sizeof(FlacMuxerContext),
164 .mime_type = "audio/x-flac",
165 .extensions = "flac",
166 .audio_codec = AV_CODEC_ID_FLAC,
167 .video_codec = AV_CODEC_ID_NONE,
168 .write_header = flac_write_header,
169 .write_packet = flac_write_packet,
170 .write_trailer = flac_write_trailer,
171 .flags = AVFMT_NOTIMESTAMPS,
172 .priv_class = &flac_muxer_class,