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1 /*
2  * Tiertex Limited SEQ File Demuxer
3  * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
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  * Tiertex Limited SEQ file demuxer
25  */
26 
27 #include "libavutil/channel_layout.h"
28 #include "avformat.h"
29 #include "internal.h"
30 
31 #define SEQ_FRAME_SIZE         6144
32 #define SEQ_FRAME_W            256
33 #define SEQ_FRAME_H            128
34 #define SEQ_NUM_FRAME_BUFFERS  30
35 #define SEQ_AUDIO_BUFFER_SIZE  882
36 #define SEQ_SAMPLE_RATE        22050
37 #define SEQ_FRAME_RATE         25
38 
39 
40 typedef struct TiertexSeqFrameBuffer {
41     int fill_size;
42     int data_size;
43     unsigned char *data;
44 } TiertexSeqFrameBuffer;
45 
46 typedef struct SeqDemuxContext {
47     int audio_stream_index;
48     int video_stream_index;
49     int current_frame_pts;
50     int current_frame_offs;
51     TiertexSeqFrameBuffer frame_buffers[SEQ_NUM_FRAME_BUFFERS];
52     int frame_buffers_count;
53     unsigned int current_audio_data_size;
54     unsigned int current_audio_data_offs;
55     unsigned int current_pal_data_size;
56     unsigned int current_pal_data_offs;
57     unsigned int current_video_data_size;
58     unsigned char *current_video_data_ptr;
59     int audio_buffer_full;
60 } SeqDemuxContext;
61 
62 
seq_probe(const AVProbeData * p)63 static int seq_probe(const AVProbeData *p)
64 {
65     int i;
66 
67     if (p->buf_size < 258)
68         return 0;
69 
70     /* there's no real header in a .seq file, the only thing they have in common */
71     /* is the first 256 bytes of the file which are always filled with 0 */
72     for (i = 0; i < 256; i++)
73         if (p->buf[i])
74             return 0;
75 
76     if(p->buf[256]==0 && p->buf[257]==0)
77         return 0;
78 
79     /* only one fourth of the score since the previous check is too naive */
80     return AVPROBE_SCORE_MAX / 4;
81 }
82 
seq_init_frame_buffers(SeqDemuxContext * seq,AVIOContext * pb)83 static int seq_init_frame_buffers(SeqDemuxContext *seq, AVIOContext *pb)
84 {
85     int i, sz;
86     TiertexSeqFrameBuffer *seq_buffer;
87 
88     avio_seek(pb, 256, SEEK_SET);
89 
90     for (i = 0; i < SEQ_NUM_FRAME_BUFFERS; i++) {
91         sz = avio_rl16(pb);
92         if (sz == 0)
93             break;
94         else {
95             seq_buffer = &seq->frame_buffers[i];
96             seq_buffer->fill_size = 0;
97             seq_buffer->data_size = sz;
98             seq_buffer->data = av_malloc(sz);
99             if (!seq_buffer->data)
100                 return AVERROR(ENOMEM);
101         }
102     }
103     seq->frame_buffers_count = i;
104     return 0;
105 }
106 
seq_fill_buffer(SeqDemuxContext * seq,AVIOContext * pb,int buffer_num,unsigned int data_offs,int data_size)107 static int seq_fill_buffer(SeqDemuxContext *seq, AVIOContext *pb, int buffer_num, unsigned int data_offs, int data_size)
108 {
109     TiertexSeqFrameBuffer *seq_buffer;
110 
111     if (buffer_num >= SEQ_NUM_FRAME_BUFFERS)
112         return AVERROR_INVALIDDATA;
113 
114     seq_buffer = &seq->frame_buffers[buffer_num];
115     if (seq_buffer->fill_size + data_size > seq_buffer->data_size || data_size <= 0)
116         return AVERROR_INVALIDDATA;
117 
118     avio_seek(pb, seq->current_frame_offs + data_offs, SEEK_SET);
119     if (avio_read(pb, seq_buffer->data + seq_buffer->fill_size, data_size) != data_size)
120         return AVERROR(EIO);
121 
122     seq_buffer->fill_size += data_size;
123     return 0;
124 }
125 
seq_parse_frame_data(SeqDemuxContext * seq,AVIOContext * pb)126 static int seq_parse_frame_data(SeqDemuxContext *seq, AVIOContext *pb)
127 {
128     unsigned int offset_table[4], buffer_num[4];
129     TiertexSeqFrameBuffer *seq_buffer;
130     int i, e, err;
131 
132     seq->current_frame_offs += SEQ_FRAME_SIZE;
133     avio_seek(pb, seq->current_frame_offs, SEEK_SET);
134 
135     /* sound data */
136     seq->current_audio_data_offs = avio_rl16(pb);
137     if (seq->current_audio_data_offs) {
138         seq->current_audio_data_size = SEQ_AUDIO_BUFFER_SIZE * 2;
139     } else {
140         seq->current_audio_data_size = 0;
141     }
142 
143     /* palette data */
144     seq->current_pal_data_offs = avio_rl16(pb);
145     if (seq->current_pal_data_offs) {
146         seq->current_pal_data_size = 768;
147     } else {
148         seq->current_pal_data_size = 0;
149     }
150 
151     /* video data */
152     for (i = 0; i < 4; i++)
153         buffer_num[i] = avio_r8(pb);
154 
155     for (i = 0; i < 4; i++)
156         offset_table[i] = avio_rl16(pb);
157 
158     for (i = 0; i < 3; i++) {
159         if (offset_table[i]) {
160             for (e = i + 1; e < 3 && offset_table[e] == 0; e++);
161             err = seq_fill_buffer(seq, pb, buffer_num[1 + i],
162               offset_table[i],
163               offset_table[e] - offset_table[i]);
164             if (err)
165                 return err;
166         }
167     }
168 
169     if (buffer_num[0] != 255) {
170         if (buffer_num[0] >= SEQ_NUM_FRAME_BUFFERS)
171             return AVERROR_INVALIDDATA;
172 
173         seq_buffer = &seq->frame_buffers[buffer_num[0]];
174         seq->current_video_data_size = seq_buffer->fill_size;
175         seq->current_video_data_ptr  = seq_buffer->data;
176         seq_buffer->fill_size = 0;
177     } else {
178         seq->current_video_data_size = 0;
179         seq->current_video_data_ptr  = 0;
180     }
181 
182     return 0;
183 }
184 
seq_read_close(AVFormatContext * s)185 static int seq_read_close(AVFormatContext *s)
186 {
187     int i;
188     SeqDemuxContext *seq = s->priv_data;
189 
190     for (i = 0; i < SEQ_NUM_FRAME_BUFFERS; i++)
191         av_freep(&seq->frame_buffers[i].data);
192 
193     return 0;
194 }
195 
seq_read_header(AVFormatContext * s)196 static int seq_read_header(AVFormatContext *s)
197 {
198     int i, rc;
199     SeqDemuxContext *seq = s->priv_data;
200     AVIOContext *pb = s->pb;
201     AVStream *st;
202 
203     /* init internal buffers */
204     rc = seq_init_frame_buffers(seq, pb);
205     if (rc < 0)
206         return rc;
207 
208     seq->current_frame_offs = 0;
209 
210     /* preload (no audio data, just buffer operations related data) */
211     for (i = 1; i <= 100; i++) {
212         rc = seq_parse_frame_data(seq, pb);
213         if (rc < 0)
214             return rc;
215     }
216 
217     seq->current_frame_pts = 0;
218 
219     seq->audio_buffer_full = 0;
220 
221     /* initialize the video decoder stream */
222     st = avformat_new_stream(s, NULL);
223     if (!st)
224         return AVERROR(ENOMEM);
225 
226     avpriv_set_pts_info(st, 32, 1, SEQ_FRAME_RATE);
227     seq->video_stream_index = st->index;
228     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
229     st->codecpar->codec_id = AV_CODEC_ID_TIERTEXSEQVIDEO;
230     st->codecpar->codec_tag = 0;  /* no fourcc */
231     st->codecpar->width = SEQ_FRAME_W;
232     st->codecpar->height = SEQ_FRAME_H;
233 
234     /* initialize the audio decoder stream */
235     st = avformat_new_stream(s, NULL);
236     if (!st)
237         return AVERROR(ENOMEM);
238 
239     st->start_time = 0;
240     avpriv_set_pts_info(st, 32, 1, SEQ_SAMPLE_RATE);
241     seq->audio_stream_index = st->index;
242     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
243     st->codecpar->codec_id = AV_CODEC_ID_PCM_S16BE;
244     st->codecpar->codec_tag = 0;  /* no tag */
245     st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
246     st->codecpar->sample_rate = SEQ_SAMPLE_RATE;
247     st->codecpar->bits_per_coded_sample = 16;
248     st->codecpar->bit_rate = st->codecpar->sample_rate * st->codecpar->bits_per_coded_sample * st->codecpar->ch_layout.nb_channels;
249     st->codecpar->block_align = st->codecpar->ch_layout.nb_channels * st->codecpar->bits_per_coded_sample / 8;
250 
251     return 0;
252 }
253 
seq_read_packet(AVFormatContext * s,AVPacket * pkt)254 static int seq_read_packet(AVFormatContext *s, AVPacket *pkt)
255 {
256     int rc;
257     SeqDemuxContext *seq = s->priv_data;
258     AVIOContext *pb = s->pb;
259 
260     if (!seq->audio_buffer_full) {
261         rc = seq_parse_frame_data(seq, pb);
262         if (rc)
263             return rc;
264 
265         /* video packet */
266         if (seq->current_pal_data_size + seq->current_video_data_size != 0) {
267             rc = av_new_packet(pkt, 1 + seq->current_pal_data_size
268                                       + seq->current_video_data_size);
269             if (rc < 0)
270                 return rc;
271 
272             pkt->data[0] = 0;
273             if (seq->current_pal_data_size) {
274                 pkt->data[0] |= 1;
275                 avio_seek(pb, seq->current_frame_offs + seq->current_pal_data_offs, SEEK_SET);
276                 if (avio_read(pb, &pkt->data[1], seq->current_pal_data_size) != seq->current_pal_data_size)
277                     return AVERROR(EIO);
278             }
279             if (seq->current_video_data_size) {
280                 pkt->data[0] |= 2;
281                 memcpy(&pkt->data[1 + seq->current_pal_data_size],
282                   seq->current_video_data_ptr,
283                   seq->current_video_data_size);
284             }
285             pkt->stream_index = seq->video_stream_index;
286             pkt->pts = seq->current_frame_pts;
287 
288             /* sound buffer will be processed on next read_packet() call */
289             seq->audio_buffer_full = 1;
290             return 0;
291        }
292     }
293 
294     /* audio packet */
295     if (seq->current_audio_data_offs == 0) /* end of data reached */
296         return AVERROR(EIO);
297 
298     avio_seek(pb, seq->current_frame_offs + seq->current_audio_data_offs, SEEK_SET);
299     rc = av_get_packet(pb, pkt, seq->current_audio_data_size);
300     if (rc < 0)
301         return rc;
302 
303     pkt->stream_index = seq->audio_stream_index;
304     seq->current_frame_pts++;
305 
306     seq->audio_buffer_full = 0;
307     return 0;
308 }
309 
310 const AVInputFormat ff_tiertexseq_demuxer = {
311     .name           = "tiertexseq",
312     .long_name      = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ"),
313     .priv_data_size = sizeof(SeqDemuxContext),
314     .flags_internal = FF_FMT_INIT_CLEANUP,
315     .read_probe     = seq_probe,
316     .read_header    = seq_read_header,
317     .read_packet    = seq_read_packet,
318     .read_close     = seq_read_close,
319 };
320