| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * MCA demuxer | ||
| 3 | * Copyright (c) 2020 Zixing Liu | ||
| 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/intreadwrite.h" | ||
| 23 | #include "avformat.h" | ||
| 24 | #include "avio_internal.h" | ||
| 25 | #include "demux.h" | ||
| 26 | #include "internal.h" | ||
| 27 | |||
| 28 | typedef struct MCADemuxContext { | ||
| 29 | uint32_t block_count; | ||
| 30 | uint16_t block_size; | ||
| 31 | uint32_t current_block; | ||
| 32 | uint32_t data_start; | ||
| 33 | uint32_t samples_per_block; | ||
| 34 | } MCADemuxContext; | ||
| 35 | |||
| 36 | 8064 | static int probe(const AVProbeData *p) | |
| 37 | { | ||
| 38 |
1/2✗ Branch 0 not taken.
✓ Branch 1 taken 8064 times.
|
8064 | if (AV_RL32(p->buf) == MKTAG('M', 'A', 'D', 'P') && |
| 39 | ✗ | AV_RL16(p->buf + 4) <= 0x5) | |
| 40 | ✗ | return AVPROBE_SCORE_MAX / 3 * 2; | |
| 41 | 8064 | return 0; | |
| 42 | } | ||
| 43 | |||
| 44 | ✗ | static int read_header(AVFormatContext *s) | |
| 45 | { | ||
| 46 | AVStream *st; | ||
| 47 | ✗ | MCADemuxContext *m = s->priv_data; | |
| 48 | AVCodecParameters *par; | ||
| 49 | ✗ | int64_t file_size = avio_size(s->pb); | |
| 50 | ✗ | uint16_t version = 0; | |
| 51 | uint32_t header_size, data_size, data_offset, loop_start, loop_end, | ||
| 52 | ✗ | nb_samples, nb_metadata, coef_offset = 0; | |
| 53 | int ch, ret; | ||
| 54 | int64_t ret_size; | ||
| 55 | |||
| 56 | ✗ | st = avformat_new_stream(s, NULL); | |
| 57 | ✗ | if (!st) | |
| 58 | ✗ | return AVERROR(ENOMEM); | |
| 59 | ✗ | par = st->codecpar; | |
| 60 | ✗ | par->codec_type = AVMEDIA_TYPE_AUDIO; | |
| 61 | |||
| 62 | // parse file headers | ||
| 63 | ✗ | avio_skip(s->pb, 0x4); // skip the file magic | |
| 64 | ✗ | version = avio_rl16(s->pb); | |
| 65 | ✗ | avio_skip(s->pb, 0x2); // padding | |
| 66 | ✗ | par->ch_layout.nb_channels = avio_r8(s->pb); | |
| 67 | ✗ | avio_skip(s->pb, 0x1); // padding | |
| 68 | ✗ | m->block_size = avio_rl16(s->pb); | |
| 69 | ✗ | nb_samples = avio_rl32(s->pb); | |
| 70 | ✗ | par->sample_rate = avio_rl32(s->pb); | |
| 71 | ✗ | loop_start = avio_rl32(s->pb); | |
| 72 | ✗ | loop_end = avio_rl32(s->pb); | |
| 73 | ✗ | header_size = avio_rl32(s->pb); | |
| 74 | ✗ | data_size = avio_rl32(s->pb); | |
| 75 | ✗ | avio_skip(s->pb, 0x4); | |
| 76 | ✗ | nb_metadata = avio_rl16(s->pb); | |
| 77 | ✗ | avio_skip(s->pb, 0x2); // unknown u16 field | |
| 78 | |||
| 79 | // samples per frame = 14; frame size = 8 (2^3) | ||
| 80 | ✗ | m->samples_per_block = (m->block_size * 14) >> 3; | |
| 81 | |||
| 82 | ✗ | if (m->samples_per_block < 1) | |
| 83 | ✗ | return AVERROR_INVALIDDATA; | |
| 84 | |||
| 85 | ✗ | m->block_count = nb_samples / m->samples_per_block; | |
| 86 | ✗ | st->duration = nb_samples; | |
| 87 | |||
| 88 | // sanity checks | ||
| 89 | ✗ | if (!par->ch_layout.nb_channels || par->sample_rate <= 0 | |
| 90 | ✗ | || loop_start > loop_end || m->block_count < 1) | |
| 91 | ✗ | return AVERROR_INVALIDDATA; | |
| 92 | ✗ | if ((ret = av_dict_set_int(&s->metadata, "loop_start", | |
| 93 | av_rescale(loop_start, AV_TIME_BASE, | ||
| 94 | ✗ | par->sample_rate), 0)) < 0) | |
| 95 | ✗ | return ret; | |
| 96 | ✗ | if ((ret = av_dict_set_int(&s->metadata, "loop_end", | |
| 97 | av_rescale(loop_end, AV_TIME_BASE, | ||
| 98 | ✗ | par->sample_rate), 0)) < 0) | |
| 99 | ✗ | return ret; | |
| 100 | ✗ | if ((32 + 4 + m->block_size) > (INT_MAX / par->ch_layout.nb_channels) || | |
| 101 | ✗ | (32 + 4 + m->block_size) * par->ch_layout.nb_channels > INT_MAX - 8) | |
| 102 | ✗ | return AVERROR_INVALIDDATA; | |
| 103 | ✗ | avpriv_set_pts_info(st, 64, 1, par->sample_rate); | |
| 104 | |||
| 105 | ✗ | if (version <= 4) { | |
| 106 | // version <= 4 needs to use the file size to calculate the offsets | ||
| 107 | ✗ | if (file_size < 0) { | |
| 108 | ✗ | return AVERROR_INVALIDDATA; | |
| 109 | } | ||
| 110 | ✗ | if (file_size - data_size > UINT32_MAX) | |
| 111 | ✗ | return AVERROR_INVALIDDATA; | |
| 112 | ✗ | m->data_start = file_size - data_size; | |
| 113 | ✗ | if (version <= 3) { | |
| 114 | ✗ | nb_metadata = 0; | |
| 115 | // header_size is not available or incorrect in older versions | ||
| 116 | ✗ | header_size = m->data_start; | |
| 117 | } | ||
| 118 | ✗ | } else if (version == 5) { | |
| 119 | // read data_start location from the header | ||
| 120 | ✗ | if (0x30 * par->ch_layout.nb_channels + 0x4 > header_size) | |
| 121 | ✗ | return AVERROR_INVALIDDATA; | |
| 122 | ✗ | data_offset = header_size - 0x30 * par->ch_layout.nb_channels - 0x4; | |
| 123 | ✗ | if ((ret_size = avio_seek(s->pb, data_offset, SEEK_SET)) < 0) | |
| 124 | ✗ | return ret_size; | |
| 125 | ✗ | m->data_start = avio_rl32(s->pb); | |
| 126 | // check if the metadata is reasonable | ||
| 127 | ✗ | if (file_size > 0 && (int64_t)m->data_start + data_size > file_size) { | |
| 128 | // the header is broken beyond repair | ||
| 129 | ✗ | if ((int64_t)header_size + data_size > file_size) { | |
| 130 | ✗ | av_log(s, AV_LOG_ERROR, | |
| 131 | "MCA metadata corrupted, unable to determine the data offset.\n"); | ||
| 132 | ✗ | return AVERROR_INVALIDDATA; | |
| 133 | } | ||
| 134 | // recover the data_start information from the data size | ||
| 135 | ✗ | av_log(s, AV_LOG_WARNING, | |
| 136 | "Incorrect header size found in metadata, " | ||
| 137 | "header size approximated from the data size\n"); | ||
| 138 | ✗ | if (file_size - data_offset > UINT32_MAX) | |
| 139 | ✗ | return AVERROR_INVALIDDATA; | |
| 140 | ✗ | m->data_start = file_size - data_size; | |
| 141 | } | ||
| 142 | } else { | ||
| 143 | ✗ | avpriv_request_sample(s, "version %d", version); | |
| 144 | ✗ | return AVERROR_PATCHWELCOME; | |
| 145 | } | ||
| 146 | |||
| 147 | // coefficient alignment = 0x30; metadata size = 0x14 | ||
| 148 | ✗ | if (0x30 * par->ch_layout.nb_channels + nb_metadata * 0x14 > header_size) | |
| 149 | ✗ | return AVERROR_INVALIDDATA; | |
| 150 | ✗ | coef_offset = | |
| 151 | ✗ | header_size - 0x30 * par->ch_layout.nb_channels + nb_metadata * 0x14; | |
| 152 | |||
| 153 | ✗ | st->start_time = 0; | |
| 154 | ✗ | par->codec_id = AV_CODEC_ID_ADPCM_THP_LE; | |
| 155 | |||
| 156 | ✗ | ret = ff_alloc_extradata(st->codecpar, 32 * par->ch_layout.nb_channels); | |
| 157 | ✗ | if (ret < 0) | |
| 158 | ✗ | return ret; | |
| 159 | |||
| 160 | ✗ | if ((ret_size = avio_seek(s->pb, coef_offset, SEEK_SET)) < 0) | |
| 161 | ✗ | return ret_size; | |
| 162 | ✗ | for (ch = 0; ch < par->ch_layout.nb_channels; ch++) { | |
| 163 | ✗ | if ((ret = ffio_read_size(s->pb, par->extradata + ch * 32, 32)) < 0) | |
| 164 | ✗ | return ret; | |
| 165 | // 0x30 (alignment) - 0x20 (actual size, 32) = 0x10 (padding) | ||
| 166 | ✗ | avio_skip(s->pb, 0x10); | |
| 167 | } | ||
| 168 | |||
| 169 | // seek to the beginning of the adpcm data | ||
| 170 | // there are some files where the adpcm audio data is not immediately after the header | ||
| 171 | ✗ | if ((ret_size = avio_seek(s->pb, m->data_start, SEEK_SET)) < 0) | |
| 172 | ✗ | return ret_size; | |
| 173 | |||
| 174 | ✗ | return 0; | |
| 175 | } | ||
| 176 | |||
| 177 | ✗ | static int read_packet(AVFormatContext *s, AVPacket *pkt) | |
| 178 | { | ||
| 179 | ✗ | AVCodecParameters *par = s->streams[0]->codecpar; | |
| 180 | ✗ | MCADemuxContext *m = s->priv_data; | |
| 181 | ✗ | uint16_t size = m->block_size; | |
| 182 | ✗ | uint32_t samples = m->samples_per_block; | |
| 183 | ✗ | int ret = 0; | |
| 184 | |||
| 185 | ✗ | if (avio_feof(s->pb)) | |
| 186 | ✗ | return AVERROR_EOF; | |
| 187 | ✗ | m->current_block++; | |
| 188 | ✗ | if (m->current_block > m->block_count) | |
| 189 | ✗ | return AVERROR_EOF; | |
| 190 | |||
| 191 | ✗ | if ((ret = av_get_packet(s->pb, pkt, size * par->ch_layout.nb_channels)) < 0) | |
| 192 | ✗ | return ret; | |
| 193 | ✗ | pkt->duration = samples; | |
| 194 | ✗ | pkt->stream_index = 0; | |
| 195 | |||
| 196 | ✗ | return 0; | |
| 197 | } | ||
| 198 | |||
| 199 | ✗ | static int read_seek(AVFormatContext *s, int stream_index, | |
| 200 | int64_t timestamp, int flags) | ||
| 201 | { | ||
| 202 | ✗ | AVStream *st = s->streams[stream_index]; | |
| 203 | ✗ | MCADemuxContext *m = s->priv_data; | |
| 204 | ✗ | int64_t ret = 0; | |
| 205 | |||
| 206 | ✗ | if (timestamp < 0) | |
| 207 | ✗ | timestamp = 0; | |
| 208 | ✗ | timestamp /= m->samples_per_block; | |
| 209 | ✗ | if (timestamp >= m->block_count) | |
| 210 | ✗ | timestamp = m->block_count - 1; | |
| 211 | ✗ | ret = avio_seek(s->pb, m->data_start + timestamp * m->block_size * | |
| 212 | ✗ | st->codecpar->ch_layout.nb_channels, SEEK_SET); | |
| 213 | ✗ | if (ret < 0) | |
| 214 | ✗ | return ret; | |
| 215 | |||
| 216 | ✗ | m->current_block = timestamp; | |
| 217 | ✗ | avpriv_update_cur_dts(s, st, timestamp * m->samples_per_block); | |
| 218 | ✗ | return 0; | |
| 219 | } | ||
| 220 | |||
| 221 | const FFInputFormat ff_mca_demuxer = { | ||
| 222 | .p.name = "mca", | ||
| 223 | .p.long_name = NULL_IF_CONFIG_SMALL("MCA Audio Format"), | ||
| 224 | .p.extensions = "mca", | ||
| 225 | .priv_data_size = sizeof(MCADemuxContext), | ||
| 226 | .read_probe = probe, | ||
| 227 | .read_header = read_header, | ||
| 228 | .read_packet = read_packet, | ||
| 229 | .read_seek = read_seek, | ||
| 230 | }; | ||
| 231 |