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 "libavcodec/flac.h"
23#include "avformat.h"
24#include "flacenc.h"
25#include "metadata.h"
26#include "vorbiscomment.h"
27#include "libavcodec/bytestream.h"
28
29
30static int flac_write_block_padding(ByteIOContext *pb, unsigned int n_padding_bytes,
31                                    int last_block)
32{
33    put_byte(pb, last_block ? 0x81 : 0x01);
34    put_be24(pb, n_padding_bytes);
35    while (n_padding_bytes > 0) {
36        put_byte(pb, 0);
37        n_padding_bytes--;
38    }
39    return 0;
40}
41
42static int flac_write_block_comment(ByteIOContext *pb, AVMetadata *m,
43                                    int last_block, int bitexact)
44{
45    const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT;
46    unsigned int len, count;
47    uint8_t *p, *p0;
48
49    len = ff_vorbiscomment_length(m, vendor, &count);
50    p0 = av_malloc(len+4);
51    if (!p0)
52        return AVERROR(ENOMEM);
53    p = p0;
54
55    bytestream_put_byte(&p, last_block ? 0x84 : 0x04);
56    bytestream_put_be24(&p, len);
57    ff_vorbiscomment_write(&p, m, vendor, count);
58
59    put_buffer(pb, p0, len+4);
60    av_freep(&p0);
61    p = NULL;
62
63    return 0;
64}
65
66static int flac_write_header(struct AVFormatContext *s)
67{
68    int ret;
69    AVCodecContext *codec = s->streams[0]->codec;
70
71    ret = ff_flac_write_header(s->pb, codec, 0);
72    if (ret)
73        return ret;
74
75    ret = flac_write_block_comment(s->pb, s->metadata, 0,
76                                   codec->flags & CODEC_FLAG_BITEXACT);
77    if (ret)
78        return ret;
79
80    /* The command line flac encoder defaults to placing a seekpoint
81     * every 10s.  So one might add padding to allow that later
82     * but there seems to be no simple way to get the duration here.
83     * So let's try the flac default of 8192 bytes */
84    flac_write_block_padding(s->pb, 8192, 1);
85
86    return ret;
87}
88
89static int flac_write_trailer(struct AVFormatContext *s)
90{
91    ByteIOContext *pb = s->pb;
92    uint8_t *streaminfo;
93    enum FLACExtradataFormat format;
94    int64_t file_size;
95
96    if (!ff_flac_is_extradata_valid(s->streams[0]->codec, &format, &streaminfo))
97        return -1;
98
99    if (!url_is_streamed(pb)) {
100        /* rewrite the STREAMINFO header block data */
101        file_size = url_ftell(pb);
102        url_fseek(pb, 8, SEEK_SET);
103        put_buffer(pb, streaminfo, FLAC_STREAMINFO_SIZE);
104        url_fseek(pb, file_size, SEEK_SET);
105        put_flush_packet(pb);
106    } else {
107        av_log(s, AV_LOG_WARNING, "unable to rewrite FLAC header.\n");
108    }
109    return 0;
110}
111
112static int flac_write_packet(struct AVFormatContext *s, AVPacket *pkt)
113{
114    put_buffer(s->pb, pkt->data, pkt->size);
115    put_flush_packet(s->pb);
116    return 0;
117}
118
119AVOutputFormat flac_muxer = {
120    "flac",
121    NULL_IF_CONFIG_SMALL("raw FLAC"),
122    "audio/x-flac",
123    "flac",
124    0,
125    CODEC_ID_FLAC,
126    CODEC_ID_NONE,
127    flac_write_header,
128    flac_write_packet,
129    flac_write_trailer,
130    .flags= AVFMT_NOTIMESTAMPS,
131    .metadata_conv = ff_vorbiscomment_metadata_conv,
132};
133