| 1 | /* |
| 2 | * raw FLAC muxer |
| 3 | * Copyright (c) 2006-2009 Justin Ruggles |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 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. |
| 11 | * |
| 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. |
| 16 | * |
| 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 |
| 20 | */ |
| 21 | |
| 22 | #include "libavutil/channel_layout.h" |
| 23 | #include "libavutil/opt.h" |
| 24 | #include "libavcodec/flac.h" |
| 25 | #include "avformat.h" |
| 26 | #include "avio_internal.h" |
| 27 | #include "flacenc.h" |
| 28 | #include "vorbiscomment.h" |
| 29 | #include "libavcodec/bytestream.h" |
| 30 | |
| 31 | |
| 32 | typedef struct FlacMuxerContext { |
| 33 | const AVClass *class; |
| 34 | int write_header; |
| 35 | |
| 36 | /* updated streaminfo sent by the encoder at the end */ |
| 37 | uint8_t *streaminfo; |
| 38 | } FlacMuxerContext; |
| 39 | |
| 40 | static int flac_write_block_padding(AVIOContext *pb, unsigned int n_padding_bytes, |
| 41 | int last_block) |
| 42 | { |
| 43 | avio_w8(pb, last_block ? 0x81 : 0x01); |
| 44 | avio_wb24(pb, n_padding_bytes); |
| 45 | ffio_fill(pb, 0, n_padding_bytes); |
| 46 | return 0; |
| 47 | } |
| 48 | |
| 49 | static int flac_write_block_comment(AVIOContext *pb, AVDictionary **m, |
| 50 | int last_block, int bitexact) |
| 51 | { |
| 52 | const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT; |
| 53 | unsigned int len; |
| 54 | uint8_t *p, *p0; |
| 55 | |
| 56 | ff_metadata_conv(m, ff_vorbiscomment_metadata_conv, NULL); |
| 57 | |
| 58 | len = ff_vorbiscomment_length(*m, vendor); |
| 59 | p0 = av_malloc(len+4); |
| 60 | if (!p0) |
| 61 | return AVERROR(ENOMEM); |
| 62 | p = p0; |
| 63 | |
| 64 | bytestream_put_byte(&p, last_block ? 0x84 : 0x04); |
| 65 | bytestream_put_be24(&p, len); |
| 66 | ff_vorbiscomment_write(&p, m, vendor); |
| 67 | |
| 68 | avio_write(pb, p0, len+4); |
| 69 | av_freep(&p0); |
| 70 | p = NULL; |
| 71 | |
| 72 | return 0; |
| 73 | } |
| 74 | |
| 75 | static int flac_write_header(struct AVFormatContext *s) |
| 76 | { |
| 77 | int ret; |
| 78 | int padding = s->metadata_header_padding; |
| 79 | AVCodecContext *codec = s->streams[0]->codec; |
| 80 | FlacMuxerContext *c = s->priv_data; |
| 81 | |
| 82 | if (!c->write_header) |
| 83 | return 0; |
| 84 | |
| 85 | if (s->nb_streams > 1) { |
| 86 | av_log(s, AV_LOG_ERROR, "only one stream is supported\n"); |
| 87 | return AVERROR(EINVAL); |
| 88 | } |
| 89 | if (codec->codec_id != AV_CODEC_ID_FLAC) { |
| 90 | av_log(s, AV_LOG_ERROR, "unsupported codec\n"); |
| 91 | return AVERROR(EINVAL); |
| 92 | } |
| 93 | |
| 94 | if (padding < 0) |
| 95 | padding = 8192; |
| 96 | /* The FLAC specification states that 24 bits are used to represent the |
| 97 | * size of a metadata block so we must clip this value to 2^24-1. */ |
| 98 | padding = av_clip(padding, 0, 16777215); |
| 99 | |
| 100 | ret = ff_flac_write_header(s->pb, codec->extradata, |
| 101 | codec->extradata_size, 0); |
| 102 | if (ret) |
| 103 | return ret; |
| 104 | |
| 105 | /* add the channel layout tag */ |
| 106 | if (codec->channel_layout && |
| 107 | !(codec->channel_layout & ~0x3ffffULL) && |
| 108 | !ff_flac_is_native_layout(codec->channel_layout)) { |
| 109 | AVDictionaryEntry *chmask = av_dict_get(s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", |
| 110 | NULL, 0); |
| 111 | |
| 112 | if (chmask) { |
| 113 | av_log(s, AV_LOG_WARNING, "A WAVEFORMATEXTENSIBLE_CHANNEL_MASK is " |
| 114 | "already present, this muxer will not overwrite it.\n"); |
| 115 | } else { |
| 116 | uint8_t buf[32]; |
| 117 | snprintf(buf, sizeof(buf), "0x%"PRIx64, codec->channel_layout); |
| 118 | av_dict_set(&s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", buf, 0); |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | ret = flac_write_block_comment(s->pb, &s->metadata, !padding, |
| 123 | s->flags & AVFMT_FLAG_BITEXACT); |
| 124 | if (ret) |
| 125 | return ret; |
| 126 | |
| 127 | /* The command line flac encoder defaults to placing a seekpoint |
| 128 | * every 10s. So one might add padding to allow that later |
| 129 | * but there seems to be no simple way to get the duration here. |
| 130 | * So just add the amount requested by the user. */ |
| 131 | if (padding) |
| 132 | flac_write_block_padding(s->pb, padding, 1); |
| 133 | |
| 134 | return ret; |
| 135 | } |
| 136 | |
| 137 | static int flac_write_trailer(struct AVFormatContext *s) |
| 138 | { |
| 139 | AVIOContext *pb = s->pb; |
| 140 | int64_t file_size; |
| 141 | FlacMuxerContext *c = s->priv_data; |
| 142 | uint8_t *streaminfo = c->streaminfo ? c->streaminfo : |
| 143 | s->streams[0]->codec->extradata; |
| 144 | |
| 145 | if (!c->write_header || !streaminfo) |
| 146 | return 0; |
| 147 | |
| 148 | if (pb->seekable) { |
| 149 | /* rewrite the STREAMINFO header block data */ |
| 150 | file_size = avio_tell(pb); |
| 151 | avio_seek(pb, 8, SEEK_SET); |
| 152 | avio_write(pb, streaminfo, FLAC_STREAMINFO_SIZE); |
| 153 | avio_seek(pb, file_size, SEEK_SET); |
| 154 | avio_flush(pb); |
| 155 | } else { |
| 156 | av_log(s, AV_LOG_WARNING, "unable to rewrite FLAC header.\n"); |
| 157 | } |
| 158 | |
| 159 | av_freep(&c->streaminfo); |
| 160 | |
| 161 | return 0; |
| 162 | } |
| 163 | |
| 164 | static int flac_write_packet(struct AVFormatContext *s, AVPacket *pkt) |
| 165 | { |
| 166 | FlacMuxerContext *c = s->priv_data; |
| 167 | uint8_t *streaminfo; |
| 168 | int streaminfo_size; |
| 169 | |
| 170 | /* check for updated streaminfo */ |
| 171 | streaminfo = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, |
| 172 | &streaminfo_size); |
| 173 | if (streaminfo && streaminfo_size == FLAC_STREAMINFO_SIZE) { |
| 174 | av_freep(&c->streaminfo); |
| 175 | |
| 176 | c->streaminfo = av_malloc(FLAC_STREAMINFO_SIZE); |
| 177 | if (!c->streaminfo) |
| 178 | return AVERROR(ENOMEM); |
| 179 | memcpy(c->streaminfo, streaminfo, FLAC_STREAMINFO_SIZE); |
| 180 | } |
| 181 | |
| 182 | if (pkt->size) |
| 183 | avio_write(s->pb, pkt->data, pkt->size); |
| 184 | return 0; |
| 185 | } |
| 186 | |
| 187 | static const AVOption flacenc_options[] = { |
| 188 | { "write_header", "Write the file header", offsetof(FlacMuxerContext, write_header), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM }, |
| 189 | { NULL }, |
| 190 | }; |
| 191 | |
| 192 | static const AVClass flac_muxer_class = { |
| 193 | .class_name = "flac muxer", |
| 194 | .item_name = av_default_item_name, |
| 195 | .option = flacenc_options, |
| 196 | .version = LIBAVUTIL_VERSION_INT, |
| 197 | }; |
| 198 | |
| 199 | AVOutputFormat ff_flac_muxer = { |
| 200 | .name = "flac", |
| 201 | .long_name = NULL_IF_CONFIG_SMALL("raw FLAC"), |
| 202 | .priv_data_size = sizeof(FlacMuxerContext), |
| 203 | .mime_type = "audio/x-flac", |
| 204 | .extensions = "flac", |
| 205 | .audio_codec = AV_CODEC_ID_FLAC, |
| 206 | .video_codec = AV_CODEC_ID_NONE, |
| 207 | .write_header = flac_write_header, |
| 208 | .write_packet = flac_write_packet, |
| 209 | .write_trailer = flac_write_trailer, |
| 210 | .flags = AVFMT_NOTIMESTAMPS, |
| 211 | .priv_class = &flac_muxer_class, |
| 212 | }; |