1/* 2 * SVS demuxer 3 * Copyright (c) 2020 Paul B Mahol 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include "libavutil/channel_layout.h" 23#include "libavutil/intreadwrite.h" 24#include "avformat.h" 25#include "internal.h" 26 27static int svs_probe(const AVProbeData *p) 28{ 29 if (p->buf_size < 32) 30 return 0; 31 32 if (memcmp(p->buf, "SVS\00", 4)) 33 return 0; 34 35 if (AV_RL32(p->buf + 16) == 0) 36 return 0; 37 38 return AVPROBE_SCORE_MAX / 3; 39} 40 41static int svs_read_header(AVFormatContext *s) 42{ 43 AVStream *st; 44 uint32_t pitch; 45 46 st = avformat_new_stream(s, NULL); 47 if (!st) 48 return AVERROR(ENOMEM); 49 50 avio_skip(s->pb, 16); 51 pitch = avio_rl32(s->pb); 52 avio_skip(s->pb, 12); 53 54 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; 55 st->codecpar->codec_id = AV_CODEC_ID_ADPCM_PSX; 56 st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO; 57 st->codecpar->sample_rate = av_rescale_rnd(pitch, 48000, 4096, AV_ROUND_INF); 58 st->codecpar->block_align = 32; 59 st->start_time = 0; 60 if (s->pb->seekable & AVIO_SEEKABLE_NORMAL) 61 st->duration = av_get_audio_frame_duration2(st->codecpar, 62 avio_size(s->pb) - 32); 63 64 avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate); 65 66 return 0; 67} 68 69static int svs_read_packet(AVFormatContext *s, AVPacket *pkt) 70{ 71 int ret; 72 73 if (avio_feof(s->pb)) 74 return AVERROR_EOF; 75 76 ret = av_get_packet(s->pb, pkt, 32 * 256); 77 if (ret != 32 * 256) { 78 if (ret < 0) 79 return ret; 80 pkt->flags &= ~AV_PKT_FLAG_CORRUPT; 81 } 82 pkt->stream_index = 0; 83 84 return ret; 85} 86 87const AVInputFormat ff_svs_demuxer = { 88 .name = "svs", 89 .long_name = NULL_IF_CONFIG_SMALL("Square SVS"), 90 .read_probe = svs_probe, 91 .read_header = svs_read_header, 92 .read_packet = svs_read_packet, 93 .extensions = "svs", 94}; 95