| /* |
| * LEGO Racers ALP (.tun & .pcm) demuxer |
| * |
| * Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.com) |
| * |
| * 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 "internal.h" |
| #include "libavutil/intreadwrite.h" |
| #include "libavutil/internal.h" |
| |
| #define ALP_TAG MKTAG('A', 'L', 'P', ' ') |
| #define ALP_MAX_READ_SIZE 4096 |
| |
| typedef struct ALPHeader { |
| uint32_t magic; /*< Magic Number, {'A', 'L', 'P', ' '} */ |
| uint32_t header_size; /*< Header size (after this). */ |
| char adpcm[6]; /*< "ADPCM" */ |
| uint8_t unk1; /*< Unknown */ |
| uint8_t num_channels; /*< Channel Count. */ |
| uint32_t sample_rate; /*< Sample rate, only if header_size >= 12. */ |
| } ALPHeader; |
| |
| static int alp_probe(const AVProbeData *p) |
| { |
| uint32_t i; |
| |
| if (AV_RL32(p->buf) != ALP_TAG) |
| return 0; |
| |
| /* Only allowed header sizes are 8 and 12. */ |
| i = AV_RL32(p->buf + 4); |
| if (i != 8 && i != 12) |
| return 0; |
| |
| if (strncmp("ADPCM", p->buf + 8, 6) != 0) |
| return 0; |
| |
| return AVPROBE_SCORE_MAX - 1; |
| } |
| |
| static int alp_read_header(AVFormatContext *s) |
| { |
| int ret; |
| AVStream *st; |
| ALPHeader hdr; |
| AVCodecParameters *par; |
| |
| if ((hdr.magic = avio_rl32(s->pb)) != ALP_TAG) |
| return AVERROR_INVALIDDATA; |
| |
| hdr.header_size = avio_rl32(s->pb); |
| |
| if (hdr.header_size != 8 && hdr.header_size != 12) { |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if ((ret = avio_read(s->pb, hdr.adpcm, sizeof(hdr.adpcm))) < 0) |
| return ret; |
| else if (ret != sizeof(hdr.adpcm)) |
| return AVERROR(EIO); |
| |
| if (strncmp("ADPCM", hdr.adpcm, sizeof(hdr.adpcm)) != 0) |
| return AVERROR_INVALIDDATA; |
| |
| hdr.unk1 = avio_r8(s->pb); |
| hdr.num_channels = avio_r8(s->pb); |
| |
| if (hdr.header_size == 8) { |
| /* .TUN music file */ |
| hdr.sample_rate = 11025 * hdr.num_channels; |
| } else { |
| /* .PCM sound file */ |
| hdr.sample_rate = avio_rl32(s->pb); |
| } |
| |
| if (hdr.sample_rate > 44100) { |
| avpriv_request_sample(s, "Sample Rate > 44100"); |
| return AVERROR_PATCHWELCOME; |
| } |
| |
| if (!(st = avformat_new_stream(s, NULL))) |
| return AVERROR(ENOMEM); |
| |
| par = st->codecpar; |
| par->codec_type = AVMEDIA_TYPE_AUDIO; |
| par->codec_id = AV_CODEC_ID_ADPCM_IMA_ALP; |
| par->format = AV_SAMPLE_FMT_S16; |
| par->sample_rate = hdr.sample_rate; |
| par->channels = hdr.num_channels; |
| |
| if (hdr.num_channels == 1) |
| par->channel_layout = AV_CH_LAYOUT_MONO; |
| else if (hdr.num_channels == 2) |
| par->channel_layout = AV_CH_LAYOUT_STEREO; |
| else |
| return AVERROR_INVALIDDATA; |
| |
| par->bits_per_coded_sample = 4; |
| par->bits_per_raw_sample = 16; |
| par->block_align = 1; |
| par->bit_rate = par->channels * |
| par->sample_rate * |
| par->bits_per_coded_sample; |
| |
| avpriv_set_pts_info(st, 64, 1, par->sample_rate); |
| return 0; |
| } |
| |
| static int alp_read_packet(AVFormatContext *s, AVPacket *pkt) |
| { |
| int ret; |
| AVCodecParameters *par = s->streams[0]->codecpar; |
| |
| if ((ret = av_get_packet(s->pb, pkt, ALP_MAX_READ_SIZE)) < 0) |
| return ret; |
| |
| pkt->flags &= ~AV_PKT_FLAG_CORRUPT; |
| pkt->stream_index = 0; |
| pkt->duration = ret * 2 / par->channels; |
| |
| return 0; |
| } |
| |
| AVInputFormat ff_alp_demuxer = { |
| .name = "alp", |
| .long_name = NULL_IF_CONFIG_SMALL("LEGO Racers ALP"), |
| .read_probe = alp_probe, |
| .read_header = alp_read_header, |
| .read_packet = alp_read_packet |
| }; |