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/channel_layout.h"
23 #include "libavutil/opt.h"
24 #include "libavcodec/flac.h"
26 #include "avio_internal.h"
28 #include "vorbiscomment.h"
29 #include "libavcodec/bytestream.h"
32 typedef struct FlacMuxerContext {
36 /* updated streaminfo sent by the encoder at the end */
40 static int flac_write_block_padding(AVIOContext *pb, unsigned int n_padding_bytes,
43 avio_w8(pb, last_block ? 0x81 : 0x01);
44 avio_wb24(pb, n_padding_bytes);
45 ffio_fill(pb, 0, n_padding_bytes);
49 static int flac_write_block_comment(AVIOContext *pb, AVDictionary **m,
50 int last_block, int bitexact)
52 const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT;
56 ff_metadata_conv(m, ff_vorbiscomment_metadata_conv, NULL);
58 len = ff_vorbiscomment_length(*m, vendor);
59 if (len >= ((1<<24) - 4))
60 return AVERROR(EINVAL);
61 p0 = av_malloc(len+4);
63 return AVERROR(ENOMEM);
66 bytestream_put_byte(&p, last_block ? 0x84 : 0x04);
67 bytestream_put_be24(&p, len);
68 ff_vorbiscomment_write(&p, m, vendor);
70 avio_write(pb, p0, len+4);
77 static int flac_write_header(struct AVFormatContext *s)
80 int padding = s->metadata_header_padding;
81 AVCodecParameters *par = s->streams[0]->codecpar;
82 FlacMuxerContext *c = s->priv_data;
87 if (s->nb_streams > 1) {
88 av_log(s, AV_LOG_ERROR, "only one stream is supported\n");
89 return AVERROR(EINVAL);
91 if (par->codec_id != AV_CODEC_ID_FLAC) {
92 av_log(s, AV_LOG_ERROR, "unsupported codec\n");
93 return AVERROR(EINVAL);
98 /* The FLAC specification states that 24 bits are used to represent the
99 * size of a metadata block so we must clip this value to 2^24-1. */
100 padding = av_clip_uintp2(padding, 24);
102 ret = ff_flac_write_header(s->pb, par->extradata,
103 par->extradata_size, 0);
107 /* add the channel layout tag */
108 if (par->channel_layout &&
109 !(par->channel_layout & ~0x3ffffULL) &&
110 !ff_flac_is_native_layout(par->channel_layout)) {
111 AVDictionaryEntry *chmask = av_dict_get(s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK",
115 av_log(s, AV_LOG_WARNING, "A WAVEFORMATEXTENSIBLE_CHANNEL_MASK is "
116 "already present, this muxer will not overwrite it.\n");
119 snprintf(buf, sizeof(buf), "0x%"PRIx64, par->channel_layout);
120 av_dict_set(&s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", buf, 0);
124 ret = flac_write_block_comment(s->pb, &s->metadata, !padding,
125 s->flags & AVFMT_FLAG_BITEXACT);
129 /* The command line flac encoder defaults to placing a seekpoint
130 * every 10s. So one might add padding to allow that later
131 * but there seems to be no simple way to get the duration here.
132 * So just add the amount requested by the user. */
134 flac_write_block_padding(s->pb, padding, 1);
139 static int flac_write_trailer(struct AVFormatContext *s)
141 AVIOContext *pb = s->pb;
143 FlacMuxerContext *c = s->priv_data;
144 uint8_t *streaminfo = c->streaminfo ? c->streaminfo :
145 s->streams[0]->codecpar->extradata;
147 if (!c->write_header || !streaminfo)
150 if (pb->seekable & AVIO_SEEKABLE_NORMAL) {
151 /* rewrite the STREAMINFO header block data */
152 file_size = avio_tell(pb);
153 avio_seek(pb, 8, SEEK_SET);
154 avio_write(pb, streaminfo, FLAC_STREAMINFO_SIZE);
155 avio_seek(pb, file_size, SEEK_SET);
158 av_log(s, AV_LOG_WARNING, "unable to rewrite FLAC header.\n");
161 av_freep(&c->streaminfo);
166 static int flac_write_packet(struct AVFormatContext *s, AVPacket *pkt)
168 FlacMuxerContext *c = s->priv_data;
172 /* check for updated streaminfo */
173 streaminfo = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
175 if (streaminfo && streaminfo_size == FLAC_STREAMINFO_SIZE) {
176 av_freep(&c->streaminfo);
178 c->streaminfo = av_malloc(FLAC_STREAMINFO_SIZE);
180 return AVERROR(ENOMEM);
181 memcpy(c->streaminfo, streaminfo, FLAC_STREAMINFO_SIZE);
185 avio_write(s->pb, pkt->data, pkt->size);
189 static const AVOption flacenc_options[] = {
190 { "write_header", "Write the file header", offsetof(FlacMuxerContext, write_header), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
194 static const AVClass flac_muxer_class = {
195 .class_name = "flac muxer",
196 .item_name = av_default_item_name,
197 .option = flacenc_options,
198 .version = LIBAVUTIL_VERSION_INT,
201 AVOutputFormat ff_flac_muxer = {
203 .long_name = NULL_IF_CONFIG_SMALL("raw FLAC"),
204 .priv_data_size = sizeof(FlacMuxerContext),
205 .mime_type = "audio/x-flac",
206 .extensions = "flac",
207 .audio_codec = AV_CODEC_ID_FLAC,
208 .video_codec = AV_CODEC_ID_NONE,
209 .write_header = flac_write_header,
210 .write_packet = flac_write_packet,
211 .write_trailer = flac_write_trailer,
212 .flags = AVFMT_NOTIMESTAMPS,
213 .priv_class = &flac_muxer_class,