| /* |
| * 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(const 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) { |
| 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", |
| }; |