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/*
* RedSpark demuxer
* Copyright (c) 2013 James Almer
*
* 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 "libavcodec/bytestream.h"
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "avio.h"
#include "internal.h"
#define HEADER_SIZE 4096
#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
typedef struct RedSparkContext {
int samples_count;
} RedSparkContext;
static int redspark_probe(AVProbeData *p)
{
uint32_t key, data;
uint8_t header[8];
/* Decrypt first 8 bytes of the header */
data = AV_RB32(p->buf);
key = data ^ 0x52656453;
data ^= key;
AV_WB32(header, data);
key = rol(key, 11);
key += rol(key, 3);
data = AV_RB32(p->buf + 4) ^ key;
AV_WB32(header + 4, data);
if (AV_RB64(header) == AV_RB64("RedSpark"))
return AVPROBE_SCORE_MAX;
return 0;
}
static int redspark_read_header(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
RedSparkContext *redspark = s->priv_data;
AVCodecParameters *par;
GetByteContext gbc;
int i, coef_off, ret = 0;
uint32_t key, data;
uint8_t header[HEADER_SIZE];
AVStream *st;
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
par = st->codecpar;
/* Decrypt header */
data = avio_rb32(pb);
key = data ^ 0x52656453;
data ^= key;
AV_WB32(header, data);
key = rol(key, 11);
for (i = 4; i < HEADER_SIZE; i += 4) {
key += rol(key, 3);
data = avio_rb32(pb) ^ key;
AV_WB32(header + i, data);
}
par->codec_id = AV_CODEC_ID_ADPCM_THP;
par->codec_type = AVMEDIA_TYPE_AUDIO;
bytestream2_init(&gbc, header, HEADER_SIZE);
bytestream2_seek(&gbc, 0x3c, SEEK_SET);
par->sample_rate = bytestream2_get_be32u(&gbc);
if (par->sample_rate <= 0 || par->sample_rate > 96000) {
av_log(s, AV_LOG_ERROR, "Invalid sample rate: %d\n", par->sample_rate);
return AVERROR_INVALIDDATA;
}
st->duration = bytestream2_get_be32u(&gbc) * 14;
redspark->samples_count = 0;
bytestream2_skipu(&gbc, 10);
par->channels = bytestream2_get_byteu(&gbc);
if (!par->channels) {
return AVERROR_INVALIDDATA;
}
coef_off = 0x54 + par->channels * 8;
if (bytestream2_get_byteu(&gbc)) // Loop flag
coef_off += 16;
if (coef_off + par->channels * (32 + 14) > HEADER_SIZE) {
return AVERROR_INVALIDDATA;
}
if (ff_alloc_extradata(par, 32 * par->channels)) {
return AVERROR_INVALIDDATA;
}
/* Get the ADPCM table */
bytestream2_seek(&gbc, coef_off, SEEK_SET);
for (i = 0; i < par->channels; i++) {
if (bytestream2_get_bufferu(&gbc, par->extradata + i * 32, 32) != 32) {
return AVERROR_INVALIDDATA;
}
bytestream2_skipu(&gbc, 14);
}
avpriv_set_pts_info(st, 64, 1, par->sample_rate);
return ret;
}
static int redspark_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AVCodecParameters *par = s->streams[0]->codecpar;
RedSparkContext *redspark = s->priv_data;
uint32_t size = 8 * par->channels;
int ret;
if (avio_feof(s->pb) || redspark->samples_count == s->streams[0]->duration)
return AVERROR_EOF;
ret = av_get_packet(s->pb, pkt, size);
if (ret != size) {
av_packet_unref(pkt);
return AVERROR(EIO);
}
pkt->duration = 14;
redspark->samples_count += pkt->duration;
pkt->stream_index = 0;
return ret;
}
AVInputFormat ff_redspark_demuxer = {
.name = "redspark",
.long_name = NULL_IF_CONFIG_SMALL("RedSpark"),
.priv_data_size = sizeof(RedSparkContext),
.read_probe = redspark_probe,
.read_header = redspark_read_header,
.read_packet = redspark_read_packet,
.extensions = "rsd",
};
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