| 1 | /* |
| 2 | * 8088flex TMV file demuxer |
| 3 | * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu> |
| 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 | /** |
| 23 | * @file |
| 24 | * 8088flex TMV file demuxer |
| 25 | * @author Daniel Verkamp |
| 26 | * @see http://www.oldskool.org/pc/8088_Corruption |
| 27 | */ |
| 28 | |
| 29 | #include "libavutil/channel_layout.h" |
| 30 | #include "libavutil/intreadwrite.h" |
| 31 | #include "avformat.h" |
| 32 | #include "internal.h" |
| 33 | |
| 34 | enum { |
| 35 | TMV_PADDING = 0x01, |
| 36 | TMV_STEREO = 0x02, |
| 37 | }; |
| 38 | |
| 39 | #define TMV_TAG MKTAG('T', 'M', 'A', 'V') |
| 40 | |
| 41 | typedef struct TMVContext { |
| 42 | unsigned audio_chunk_size; |
| 43 | unsigned video_chunk_size; |
| 44 | unsigned padding; |
| 45 | unsigned stream_index; |
| 46 | } TMVContext; |
| 47 | |
| 48 | #define TMV_HEADER_SIZE 12 |
| 49 | |
| 50 | #define PROBE_MIN_SAMPLE_RATE 5000 |
| 51 | #define PROBE_MAX_FPS 120 |
| 52 | #define PROBE_MIN_AUDIO_SIZE (PROBE_MIN_SAMPLE_RATE / PROBE_MAX_FPS) |
| 53 | |
| 54 | static int tmv_probe(AVProbeData *p) |
| 55 | { |
| 56 | if (AV_RL32(p->buf) == TMV_TAG && |
| 57 | AV_RL16(p->buf+4) >= PROBE_MIN_SAMPLE_RATE && |
| 58 | AV_RL16(p->buf+6) >= PROBE_MIN_AUDIO_SIZE && |
| 59 | !p->buf[8] && // compression method |
| 60 | p->buf[9] && // char cols |
| 61 | p->buf[10]) // char rows |
| 62 | return AVPROBE_SCORE_MAX / |
| 63 | ((p->buf[9] == 40 && p->buf[10] == 25) ? 1 : 4); |
| 64 | return 0; |
| 65 | } |
| 66 | |
| 67 | static int tmv_read_header(AVFormatContext *s) |
| 68 | { |
| 69 | TMVContext *tmv = s->priv_data; |
| 70 | AVIOContext *pb = s->pb; |
| 71 | AVStream *vst, *ast; |
| 72 | AVRational fps; |
| 73 | unsigned comp_method, char_cols, char_rows, features; |
| 74 | |
| 75 | if (avio_rl32(pb) != TMV_TAG) |
| 76 | return -1; |
| 77 | |
| 78 | if (!(vst = avformat_new_stream(s, NULL))) |
| 79 | return AVERROR(ENOMEM); |
| 80 | |
| 81 | if (!(ast = avformat_new_stream(s, NULL))) |
| 82 | return AVERROR(ENOMEM); |
| 83 | |
| 84 | ast->codec->sample_rate = avio_rl16(pb); |
| 85 | if (!ast->codec->sample_rate) { |
| 86 | av_log(s, AV_LOG_ERROR, "invalid sample rate\n"); |
| 87 | return -1; |
| 88 | } |
| 89 | |
| 90 | tmv->audio_chunk_size = avio_rl16(pb); |
| 91 | if (!tmv->audio_chunk_size) { |
| 92 | av_log(s, AV_LOG_ERROR, "invalid audio chunk size\n"); |
| 93 | return -1; |
| 94 | } |
| 95 | |
| 96 | comp_method = avio_r8(pb); |
| 97 | if (comp_method) { |
| 98 | av_log(s, AV_LOG_ERROR, "unsupported compression method %d\n", |
| 99 | comp_method); |
| 100 | return -1; |
| 101 | } |
| 102 | |
| 103 | char_cols = avio_r8(pb); |
| 104 | char_rows = avio_r8(pb); |
| 105 | tmv->video_chunk_size = char_cols * char_rows * 2; |
| 106 | |
| 107 | features = avio_r8(pb); |
| 108 | if (features & ~(TMV_PADDING | TMV_STEREO)) { |
| 109 | av_log(s, AV_LOG_ERROR, "unsupported features 0x%02x\n", |
| 110 | features & ~(TMV_PADDING | TMV_STEREO)); |
| 111 | return -1; |
| 112 | } |
| 113 | |
| 114 | ast->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
| 115 | ast->codec->codec_id = AV_CODEC_ID_PCM_U8; |
| 116 | if (features & TMV_STEREO) { |
| 117 | ast->codec->channels = 2; |
| 118 | ast->codec->channel_layout = AV_CH_LAYOUT_STEREO; |
| 119 | } else { |
| 120 | ast->codec->channels = 1; |
| 121 | ast->codec->channel_layout = AV_CH_LAYOUT_MONO; |
| 122 | } |
| 123 | ast->codec->bits_per_coded_sample = 8; |
| 124 | ast->codec->bit_rate = ast->codec->sample_rate * |
| 125 | ast->codec->bits_per_coded_sample; |
| 126 | avpriv_set_pts_info(ast, 32, 1, ast->codec->sample_rate); |
| 127 | |
| 128 | fps.num = ast->codec->sample_rate * ast->codec->channels; |
| 129 | fps.den = tmv->audio_chunk_size; |
| 130 | av_reduce(&fps.num, &fps.den, fps.num, fps.den, 0xFFFFFFFFLL); |
| 131 | |
| 132 | vst->codec->codec_type = AVMEDIA_TYPE_VIDEO; |
| 133 | vst->codec->codec_id = AV_CODEC_ID_TMV; |
| 134 | vst->codec->pix_fmt = AV_PIX_FMT_PAL8; |
| 135 | vst->codec->width = char_cols * 8; |
| 136 | vst->codec->height = char_rows * 8; |
| 137 | avpriv_set_pts_info(vst, 32, fps.den, fps.num); |
| 138 | |
| 139 | if (features & TMV_PADDING) |
| 140 | tmv->padding = |
| 141 | ((tmv->video_chunk_size + tmv->audio_chunk_size + 511) & ~511) - |
| 142 | (tmv->video_chunk_size + tmv->audio_chunk_size); |
| 143 | |
| 144 | vst->codec->bit_rate = ((tmv->video_chunk_size + tmv->padding) * |
| 145 | fps.num * 8) / fps.den; |
| 146 | |
| 147 | return 0; |
| 148 | } |
| 149 | |
| 150 | static int tmv_read_packet(AVFormatContext *s, AVPacket *pkt) |
| 151 | { |
| 152 | TMVContext *tmv = s->priv_data; |
| 153 | AVIOContext *pb = s->pb; |
| 154 | int ret, pkt_size = tmv->stream_index ? |
| 155 | tmv->audio_chunk_size : tmv->video_chunk_size; |
| 156 | |
| 157 | if (avio_feof(pb)) |
| 158 | return AVERROR_EOF; |
| 159 | |
| 160 | ret = av_get_packet(pb, pkt, pkt_size); |
| 161 | |
| 162 | if (tmv->stream_index) |
| 163 | avio_skip(pb, tmv->padding); |
| 164 | |
| 165 | pkt->stream_index = tmv->stream_index; |
| 166 | tmv->stream_index ^= 1; |
| 167 | pkt->flags |= AV_PKT_FLAG_KEY; |
| 168 | |
| 169 | return ret; |
| 170 | } |
| 171 | |
| 172 | static int tmv_read_seek(AVFormatContext *s, int stream_index, |
| 173 | int64_t timestamp, int flags) |
| 174 | { |
| 175 | TMVContext *tmv = s->priv_data; |
| 176 | int64_t pos; |
| 177 | |
| 178 | if (stream_index) |
| 179 | return -1; |
| 180 | |
| 181 | pos = timestamp * |
| 182 | (tmv->audio_chunk_size + tmv->video_chunk_size + tmv->padding); |
| 183 | |
| 184 | if (avio_seek(s->pb, pos + TMV_HEADER_SIZE, SEEK_SET) < 0) |
| 185 | return -1; |
| 186 | tmv->stream_index = 0; |
| 187 | return 0; |
| 188 | } |
| 189 | |
| 190 | AVInputFormat ff_tmv_demuxer = { |
| 191 | .name = "tmv", |
| 192 | .long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"), |
| 193 | .priv_data_size = sizeof(TMVContext), |
| 194 | .read_probe = tmv_probe, |
| 195 | .read_header = tmv_read_header, |
| 196 | .read_packet = tmv_read_packet, |
| 197 | .read_seek = tmv_read_seek, |
| 198 | .flags = AVFMT_GENERIC_INDEX, |
| 199 | }; |