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FFmpeg/libavformat/aeaenc.c
Andreas Rheinhardt a24bccc238 avformat/mux: Add flag for "only default codecs allowed"
AVOutputFormat has default codecs for audio, video and subtitle
and often these are the only codecs of this type allowed.
So add a flag to AVOutputFormat so that this can be checked generically.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2024-03-22 23:57:19 +01:00

109 lines
3.6 KiB
C

/*
* MD STUDIO audio muxer
*
* Copyright (c) 2024 asivery
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avformat.h"
#include "avio_internal.h"
#include "rawenc.h"
#include "mux.h"
static int aea_write_header(AVFormatContext *s)
{
const AVDictionaryEntry *title_entry;
size_t title_length = 0;
AVStream *st = s->streams[0];
if (st->codecpar->ch_layout.nb_channels != 1 && st->codecpar->ch_layout.nb_channels != 2) {
av_log(s, AV_LOG_ERROR, "Only maximum 2 channels are supported in the audio"
" stream, %d channels were found.\n", st->codecpar->ch_layout.nb_channels);
return AVERROR(EINVAL);
}
if (st->codecpar->sample_rate != 44100) {
av_log(s, AV_LOG_ERROR, "Invalid sample rate (%d) AEA only supports 44.1kHz.\n", st->codecpar->sample_rate);
return AVERROR(EINVAL);
}
/* Write magic */
avio_wl32(s->pb, 2048);
/* Write AEA title */
title_entry = av_dict_get(st->metadata, "title", NULL, 0);
if (title_entry) {
const char *title_contents = title_entry->value;
title_length = strlen(title_contents);
if (title_length > 256) {
av_log(s, AV_LOG_WARNING, "Title too long, truncated to 256 bytes.\n");
title_length = 256;
}
avio_write(s->pb, title_contents, title_length);
}
ffio_fill(s->pb, 0, 256 - title_length);
/* Write number of frames (zero at header-writing time, will seek later), number of channels */
avio_wl32(s->pb, 0);
avio_w8(s->pb, st->codecpar->ch_layout.nb_channels);
avio_w8(s->pb, 0);
/* Pad the header to 2048 bytes */
ffio_fill(s->pb, 0, 1782);
return 0;
}
static int aea_write_trailer(struct AVFormatContext *s)
{
int64_t total_blocks;
AVIOContext *pb = s->pb;
AVStream *st = s->streams[0];
if (pb->seekable & AVIO_SEEKABLE_NORMAL) {
/* Seek to rewrite the block count. */
avio_seek(pb, 260, SEEK_SET);
total_blocks = st->nb_frames * st->codecpar->ch_layout.nb_channels;
if (total_blocks > UINT32_MAX) {
av_log(s, AV_LOG_WARNING, "Too many frames in the file to properly encode the header (%"PRId64")."
" Block count in the header will be truncated.\n", total_blocks);
total_blocks = UINT32_MAX;
}
avio_wl32(pb, total_blocks);
} else {
av_log(s, AV_LOG_WARNING, "Unable to rewrite AEA header.\n");
}
return 0;
}
const FFOutputFormat ff_aea_muxer = {
.p.name = "aea",
.p.long_name = NULL_IF_CONFIG_SMALL("MD STUDIO audio"),
.p.extensions = "aea",
.p.audio_codec = AV_CODEC_ID_ATRAC1,
.p.video_codec = AV_CODEC_ID_NONE,
.p.subtitle_codec = AV_CODEC_ID_NONE,
.flags_internal = FF_OFMT_FLAG_MAX_ONE_OF_EACH |
FF_OFMT_FLAG_ONLY_DEFAULT_CODECS,
.write_header = aea_write_header,
.write_packet = ff_raw_write_packet,
.write_trailer = aea_write_trailer,
};