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 Libav.
9 *
10 * Libav 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 * Libav 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 Libav; 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/intreadwrite.h"
26#include "avformat.h"
27#include "internal.h"
28
29typedef struct yop_dec_context {
30    AVPacket video_packet;
31
32    int odd_frame;
33    int frame_size;
34    int audio_block_length;
35    int palette_size;
36} YopDecContext;
37
38static int yop_probe(AVProbeData *probe_packet)
39{
40    if (AV_RB16(probe_packet->buf) == AV_RB16("YO")  &&
41        probe_packet->buf[6]                         &&
42        probe_packet->buf[7]                         &&
43        !(probe_packet->buf[8] & 1)                  &&
44        !(probe_packet->buf[10] & 1))
45        return AVPROBE_SCORE_MAX * 3 / 4;
46
47    return 0;
48}
49
50static int yop_read_header(AVFormatContext *s, AVFormatParameters *ap)
51{
52    YopDecContext *yop = s->priv_data;
53    AVIOContext *pb  = s->pb;
54
55    AVCodecContext *audio_dec, *video_dec;
56    AVStream *audio_stream, *video_stream;
57
58    int frame_rate, ret;
59
60    audio_stream = avformat_new_stream(s, NULL);
61    video_stream = avformat_new_stream(s, NULL);
62
63    // Extra data that will be passed to the decoder
64    video_stream->codec->extradata_size = 8;
65
66    video_stream->codec->extradata = av_mallocz(video_stream->codec->extradata_size +
67                                                FF_INPUT_BUFFER_PADDING_SIZE);
68
69    if (!video_stream->codec->extradata)
70        return AVERROR(ENOMEM);
71
72    // Audio
73    audio_dec               = audio_stream->codec;
74    audio_dec->codec_type   = AVMEDIA_TYPE_AUDIO;
75    audio_dec->codec_id     = CODEC_ID_ADPCM_IMA_WS;
76    audio_dec->channels     = 1;
77    audio_dec->sample_rate  = 22050;
78
79    // Video
80    video_dec               = video_stream->codec;
81    video_dec->codec_type   = AVMEDIA_TYPE_VIDEO;
82    video_dec->codec_id     = 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_dec->width        = avio_rl16(pb);
89    video_dec->height       = avio_rl16(pb);
90
91    video_stream->sample_aspect_ratio = (AVRational){1, 2};
92
93    ret = avio_read(pb, video_dec->extradata, 8);
94    if (ret < 8)
95        return ret < 0 ? ret : AVERROR_EOF;
96
97    yop->palette_size       = video_dec->extradata[0] * 3 + 4;
98    yop->audio_block_length = AV_RL16(video_dec->extradata + 6);
99
100    // 1840 samples per frame, 1 nibble per sample; hence 1840/2 = 920
101    if (yop->audio_block_length < 920 ||
102        yop->audio_block_length + yop->palette_size >= yop->frame_size) {
103        av_log(s, AV_LOG_ERROR, "YOP has invalid header\n");
104        return AVERROR_INVALIDDATA;
105    }
106
107    avio_seek(pb, 2048, SEEK_SET);
108
109    avpriv_set_pts_info(video_stream, 32, 1, frame_rate);
110
111    return 0;
112}
113
114static int yop_read_packet(AVFormatContext *s, AVPacket *pkt)
115{
116    YopDecContext *yop = s->priv_data;
117    AVIOContext *pb  = s->pb;
118
119    int ret;
120    int actual_video_data_size = yop->frame_size -
121                                 yop->audio_block_length - yop->palette_size;
122
123    yop->video_packet.stream_index = 1;
124
125    if (yop->video_packet.data) {
126        *pkt                   =  yop->video_packet;
127        yop->video_packet.data =  NULL;
128        yop->video_packet.size =  0;
129        pkt->data[0]           =  yop->odd_frame;
130        pkt->flags             |= AV_PKT_FLAG_KEY;
131        yop->odd_frame         ^= 1;
132        return pkt->size;
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 yop->audio_block_length;
167
168err_out:
169    av_free_packet(&yop->video_packet);
170    return ret;
171}
172
173static int yop_read_close(AVFormatContext *s)
174{
175    YopDecContext *yop = s->priv_data;
176    av_free_packet(&yop->video_packet);
177    return 0;
178}
179
180static 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    av_free_packet(&yop->video_packet);
188
189    if (!stream_index)
190        return -1;
191
192    pos_min        = s->data_offset;
193    pos_max        = avio_size(s->pb) - yop->frame_size;
194    frame_count    = (pos_max - pos_min) / yop->frame_size;
195
196    timestamp      = FFMAX(0, FFMIN(frame_count, timestamp));
197
198    frame_pos      = timestamp * yop->frame_size + pos_min;
199    yop->odd_frame = timestamp & 1;
200
201    avio_seek(s->pb, frame_pos, SEEK_SET);
202    return 0;
203}
204
205AVInputFormat ff_yop_demuxer = {
206    .name           = "yop",
207    .long_name      = NULL_IF_CONFIG_SMALL("Psygnosis YOP Format"),
208    .priv_data_size = sizeof(YopDecContext),
209    .read_probe     = yop_probe,
210    .read_header    = yop_read_header,
211    .read_packet    = yop_read_packet,
212    .read_close     = yop_read_close,
213    .read_seek      = yop_read_seek,
214    .extensions = "yop",
215    .flags = AVFMT_GENERIC_INDEX,
216};
217