1/*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#include "bsf.h"
20#include "bsf_internal.h"
21#include "libavutil/intreadwrite.h"
22#include "libavutil/opt.h"
23
24typedef struct OpusBSFContext {
25    const AVClass *class;
26    int gain;
27} OpusBSFContext;
28
29static int opus_metadata_init(AVBSFContext *bsfc)
30{
31    OpusBSFContext *s = bsfc->priv_data;
32
33    if (bsfc->par_out->extradata_size < 19)
34        return AVERROR_INVALIDDATA;
35
36    AV_WL16(bsfc->par_out->extradata + 16, s->gain);
37
38    return 0;
39}
40
41#define OFFSET(x) offsetof(OpusBSFContext, x)
42#define FLAGS (AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_BSF_PARAM)
43static const AVOption opus_metadata_options[] = {
44    { "gain", "Gain, actual amplification is pow(10, gain/(20.0*256))", OFFSET(gain),
45      AV_OPT_TYPE_INT, { .i64 = 0 }, -(INT16_MAX + 1), INT16_MAX, .flags = FLAGS },
46
47    { NULL },
48};
49
50static const AVClass opus_metadata_class = {
51    .class_name = "opus_metadata_bsf",
52    .item_name  = av_default_item_name,
53    .option     = opus_metadata_options,
54    .version    = LIBAVUTIL_VERSION_INT,
55};
56
57static const enum AVCodecID codec_ids[] = {
58    AV_CODEC_ID_OPUS, AV_CODEC_ID_NONE,
59};
60
61const FFBitStreamFilter ff_opus_metadata_bsf = {
62    .p.name         = "opus_metadata",
63    .p.codec_ids    = codec_ids,
64    .p.priv_class   = &opus_metadata_class,
65    .priv_data_size = sizeof(OpusBSFContext),
66    .init           = &opus_metadata_init,
67    .filter         = &ff_bsf_get_packet_ref,
68};
69