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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 | }; |