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/*
* RKA demuxer
* Copyright (c) 2023 Paul B Mahol
*
* 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 "libavutil/dict.h"
#include "libavutil/intreadwrite.h"
#include "apetag.h"
#include "avformat.h"
#include "avio_internal.h"
#include "demux.h"
#include "internal.h"
typedef struct RKAContext {
int total_frames, currentframe;
int frame_size;
int last_frame_size;
} RKAContext;
static int rka_probe(const AVProbeData *p)
{
if (AV_RL32(&p->buf[0]) == MKTAG('R', 'K', 'A', '7') &&
AV_RL32(&p->buf[4]) > 0 &&
AV_RL32(&p->buf[8]) > 0 &&
p->buf[12] > 0 &&
p->buf[12] <= 2 &&
(p->buf[13] == 8 || p->buf[13] == 16) &&
(p->buf[15] & 2) != 0)
return AVPROBE_SCORE_EXTENSION + 30;
return 0;
}
static int rka_read_header(AVFormatContext *s)
{
int64_t nb_samples, size_offset;
RKAContext *c = s->priv_data;
int channels, bps, samplerate;
AVCodecParameters *par;
int64_t framepos;
AVStream *st;
int ret;
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
par = st->codecpar;
ret = ff_get_extradata(s, par, s->pb, 16);
if (ret < 0)
return ret;
nb_samples = AV_RL32(par->extradata + 4);
samplerate = AV_RL32(par->extradata + 8);
channels = par->extradata[12];
if (channels == 0)
return AVERROR_INVALIDDATA;
bps = par->extradata[13];
if (bps < 8)
return AVERROR_INVALIDDATA;
size_offset = avio_rl32(s->pb);
framepos = avio_tell(s->pb);
c->frame_size = 131072;
avpriv_set_pts_info(st, 64, 1, samplerate);
st->start_time = 0;
avio_seek(s->pb, size_offset, SEEK_SET);
c->total_frames = (nb_samples + c->frame_size - 1) / c->frame_size;
c->last_frame_size = nb_samples % c->frame_size;
for (int i = 0; i < c->total_frames; i++) {
int r, end = 0;
int64_t size;
if (avio_feof(s->pb))
break;
size = avio_rl24(s->pb);
if (size == 0) {
end = 1;
size = size_offset - framepos;
if (size <= 0)
break;
}
if ((r = av_add_index_entry(st, framepos, (i * 131072LL) / (channels * (bps >> 3)),
size, 0, AVINDEX_KEYFRAME)) < 0)
return r;
framepos += size;
if (end)
break;
}
par->codec_type = AVMEDIA_TYPE_AUDIO;
par->codec_id = AV_CODEC_ID_RKA;
par->ch_layout.nb_channels = channels;
par->sample_rate = samplerate;
par->bits_per_raw_sample = bps;
st->duration = 8LL*nb_samples / (channels * bps);
if (s->pb->seekable & AVIO_SEEKABLE_NORMAL)
ff_ape_parse_tag(s);
avio_seek(s->pb, 20, SEEK_SET);
return 0;
}
static int rka_read_packet(AVFormatContext *s, AVPacket *pkt)
{
RKAContext *c = s->priv_data;
AVStream *st = s->streams[0];
FFStream *const sti = ffstream(st);
int size, ret;
if (avio_feof(s->pb))
return AVERROR_EOF;
if (c->currentframe >= sti->nb_index_entries)
return AVERROR_EOF;
size = sti->index_entries[c->currentframe].size;
ret = av_get_packet(s->pb, pkt, size);
pkt->dts = sti->index_entries[c->currentframe++].timestamp;
pkt->duration = c->currentframe == c->total_frames ? c->last_frame_size :
131072;
return ret;
}
static int rka_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
{
RKAContext *c = s->priv_data;
AVStream *st = s->streams[stream_index];
int index = av_index_search_timestamp(st, timestamp, flags);
if (index < 0)
return -1;
if (avio_seek(s->pb, ffstream(st)->index_entries[index].pos, SEEK_SET) < 0)
return -1;
c->currentframe = index;
return 0;
}
const FFInputFormat ff_rka_demuxer = {
.p.name = "rka",
.p.long_name = NULL_IF_CONFIG_SMALL("RKA (RK Audio)"),
.p.extensions = "rka",
.priv_data_size = sizeof(RKAContext),
.read_probe = rka_probe,
.read_header = rka_read_header,
.read_packet = rka_read_packet,
.read_seek = rka_read_seek,
};
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