1 /*
2 * Psygnosis YOP demuxer
3 *
4 * Copyright (C) 2010 Mohamed Naufal Basheer <naufal11@gmail.com>
5 * derived from the code by
6 * Copyright (C) 2009 Thomas P. Higdon <thomas.p.higdon@gmail.com>
7 *
8 * This file is part of FFmpeg.
9 *
10 * FFmpeg is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
13 * version 2.1 of the License, or (at your option) any later version.
14 *
15 * FFmpeg is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with FFmpeg; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25 #include "libavutil/channel_layout.h"
26 #include "libavutil/intreadwrite.h"
27 #include "avformat.h"
28 #include "internal.h"
29
30 typedef struct yop_dec_context {
31 AVPacket video_packet;
32
33 int odd_frame;
34 int frame_size;
35 int audio_block_length;
36 int palette_size;
37 } YopDecContext;
38
yop_probe(const AVProbeData * probe_packet)39 static int yop_probe(const AVProbeData *probe_packet)
40 {
41 if (AV_RB16(probe_packet->buf) == AV_RB16("YO") &&
42 probe_packet->buf[2]<10 &&
43 probe_packet->buf[3]<10 &&
44 probe_packet->buf[6] &&
45 probe_packet->buf[7] &&
46 !(probe_packet->buf[8] & 1) &&
47 !(probe_packet->buf[10] & 1) &&
48 AV_RL16(probe_packet->buf + 12 + 6) >= 920 &&
49 AV_RL16(probe_packet->buf + 12 + 6) < probe_packet->buf[12] * 3 + 4 + probe_packet->buf[7] * 2048
50 )
51 return AVPROBE_SCORE_MAX * 3 / 4;
52
53 return 0;
54 }
55
yop_read_header(AVFormatContext * s)56 static int yop_read_header(AVFormatContext *s)
57 {
58 YopDecContext *yop = s->priv_data;
59 AVIOContext *pb = s->pb;
60
61 AVCodecParameters *audio_par, *video_par;
62 AVStream *audio_stream, *video_stream;
63
64 int frame_rate, ret;
65
66 audio_stream = avformat_new_stream(s, NULL);
67 video_stream = avformat_new_stream(s, NULL);
68 if (!audio_stream || !video_stream)
69 return AVERROR(ENOMEM);
70
71 // Audio
72 audio_par = audio_stream->codecpar;
73 audio_par->codec_type = AVMEDIA_TYPE_AUDIO;
74 audio_par->codec_id = AV_CODEC_ID_ADPCM_IMA_APC;
75 audio_par->channels = 1;
76 audio_par->channel_layout = AV_CH_LAYOUT_MONO;
77 audio_par->sample_rate = 22050;
78
79 // Video
80 video_par = video_stream->codecpar;
81 video_par->codec_type = AVMEDIA_TYPE_VIDEO;
82 video_par->codec_id = AV_CODEC_ID_YOP;
83
84 avio_skip(pb, 6);
85
86 frame_rate = avio_r8(pb);
87 yop->frame_size = avio_r8(pb) * 2048;
88 video_par->width = avio_rl16(pb);
89 video_par->height = avio_rl16(pb);
90
91 video_stream->sample_aspect_ratio = (AVRational){1, 2};
92
93 ret = ff_get_extradata(s, video_par, pb, 8);
94 if (ret < 0)
95 return ret;
96
97 yop->palette_size = video_par->extradata[0] * 3 + 4;
98 yop->audio_block_length = AV_RL16(video_par->extradata + 6);
99
100 video_par->bit_rate = 8 * (yop->frame_size - yop->audio_block_length) * frame_rate;
101
102 // 1840 samples per frame, 1 nibble per sample; hence 1840/2 = 920
103 if (yop->audio_block_length < 920 ||
104 yop->audio_block_length + yop->palette_size >= yop->frame_size) {
105 av_log(s, AV_LOG_ERROR, "YOP has invalid header\n");
106 return AVERROR_INVALIDDATA;
107 }
108
109 avio_seek(pb, 2048, SEEK_SET);
110
111 avpriv_set_pts_info(video_stream, 32, 1, frame_rate);
112
113 return 0;
114 }
115
yop_read_packet(AVFormatContext * s,AVPacket * pkt)116 static int yop_read_packet(AVFormatContext *s, AVPacket *pkt)
117 {
118 YopDecContext *yop = s->priv_data;
119 AVIOContext *pb = s->pb;
120
121 int ret;
122 int actual_video_data_size = yop->frame_size -
123 yop->audio_block_length - yop->palette_size;
124
125 yop->video_packet.stream_index = 1;
126
127 if (yop->video_packet.data) {
128 av_packet_move_ref(pkt, &yop->video_packet);
129 pkt->data[0] = yop->odd_frame;
130 pkt->flags |= AV_PKT_FLAG_KEY;
131 yop->odd_frame ^= 1;
132 return 0;
133 }
134 ret = av_new_packet(&yop->video_packet,
135 yop->frame_size - yop->audio_block_length);
136 if (ret < 0)
137 return ret;
138
139 yop->video_packet.pos = avio_tell(pb);
140
141 ret = avio_read(pb, yop->video_packet.data, yop->palette_size);
142 if (ret < 0) {
143 goto err_out;
144 }else if (ret < yop->palette_size) {
145 ret = AVERROR_EOF;
146 goto err_out;
147 }
148
149 ret = av_get_packet(pb, pkt, 920);
150 if (ret < 0)
151 goto err_out;
152
153 // Set position to the start of the frame
154 pkt->pos = yop->video_packet.pos;
155
156 avio_skip(pb, yop->audio_block_length - ret);
157
158 ret = avio_read(pb, yop->video_packet.data + yop->palette_size,
159 actual_video_data_size);
160 if (ret < 0)
161 goto err_out;
162 else if (ret < actual_video_data_size)
163 av_shrink_packet(&yop->video_packet, yop->palette_size + ret);
164
165 // Arbitrarily return the audio data first
166 return 0;
167
168 err_out:
169 av_packet_unref(&yop->video_packet);
170 return ret;
171 }
172
yop_read_close(AVFormatContext * s)173 static int yop_read_close(AVFormatContext *s)
174 {
175 YopDecContext *yop = s->priv_data;
176 av_packet_unref(&yop->video_packet);
177 return 0;
178 }
179
yop_read_seek(AVFormatContext * s,int stream_index,int64_t timestamp,int flags)180 static int yop_read_seek(AVFormatContext *s, int stream_index,
181 int64_t timestamp, int flags)
182 {
183 YopDecContext *yop = s->priv_data;
184 int64_t frame_pos, pos_min, pos_max;
185 int frame_count;
186
187 if (!stream_index)
188 return -1;
189
190 pos_min = s->internal->data_offset;
191 pos_max = avio_size(s->pb) - yop->frame_size;
192 frame_count = (pos_max - pos_min) / yop->frame_size;
193
194 timestamp = FFMAX(0, FFMIN(frame_count, timestamp));
195
196 frame_pos = timestamp * yop->frame_size + pos_min;
197
198 if (avio_seek(s->pb, frame_pos, SEEK_SET) < 0)
199 return -1;
200
201 av_packet_unref(&yop->video_packet);
202 yop->odd_frame = timestamp & 1;
203
204 return 0;
205 }
206
207 AVInputFormat ff_yop_demuxer = {
208 .name = "yop",
209 .long_name = NULL_IF_CONFIG_SMALL("Psygnosis YOP"),
210 .priv_data_size = sizeof(YopDecContext),
211 .read_probe = yop_probe,
212 .read_header = yop_read_header,
213 .read_packet = yop_read_packet,
214 .read_close = yop_read_close,
215 .read_seek = yop_read_seek,
216 .extensions = "yop",
217 .flags = AVFMT_GENERIC_INDEX,
218 };
219