summaryrefslogtreecommitdiffstats
path: root/libavformat/rl2.c
blob: 8692e22afa598b089ab977cfe9e2ebc307e37e1d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
/*
 * RL2 Format Demuxer
 * Copyright (c) 2008 Sascha Sommer (saschasommer@freenet.de)
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * RL2 file demuxer
 * @file
 * @author Sascha Sommer (saschasommer@freenet.de)
 * @see http://wiki.multimedia.cx/index.php?title=RL2
 *
 * extradata:
 * 2 byte le initial drawing offset within 320x200 viewport
 * 4 byte le number of used colors
 * 256 * 3 bytes rgb palette
 * optional background_frame
 */

#include "libavutil/intreadwrite.h"
#include "libavutil/mathematics.h"
#include "avformat.h"
#include "internal.h"

#define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette

#define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
#define RLV2_TAG MKBETAG('R', 'L', 'V', '2')
#define RLV3_TAG MKBETAG('R', 'L', 'V', '3')

typedef struct Rl2DemuxContext {
    unsigned int index_pos[2];   ///< indexes in the sample tables
} Rl2DemuxContext;


/**
 * check if the file is in rl2 format
 * @param p probe buffer
 * @return 0 when the probe buffer does not contain rl2 data, > 0 otherwise
 */
static int rl2_probe(AVProbeData *p)
{

    if(AV_RB32(&p->buf[0]) != FORM_TAG)
        return 0;

    if(AV_RB32(&p->buf[8]) != RLV2_TAG &&
        AV_RB32(&p->buf[8]) != RLV3_TAG)
        return 0;

    return AVPROBE_SCORE_MAX;
}

/**
 * read rl2 header data and setup the avstreams
 * @param s demuxer context
 * @param ap format parameters
 * @return 0 on success, AVERROR otherwise
 */
static av_cold int rl2_read_header(AVFormatContext *s)
{
    AVIOContext *pb = s->pb;
    AVStream *st;
    unsigned int frame_count;
    unsigned int audio_frame_counter = 0;
    unsigned int video_frame_counter = 0;
    unsigned int back_size;
    unsigned short sound_rate;
    unsigned short rate;
    unsigned short channels;
    unsigned short def_sound_size;
    unsigned int signature;
    unsigned int pts_den = 11025; /* video only case */
    unsigned int pts_num = 1103;
    unsigned int* chunk_offset = NULL;
    int* chunk_size = NULL;
    int* audio_size = NULL;
    int i;
    int ret = 0;

    avio_skip(pb,4);          /* skip FORM tag */
    back_size = avio_rl32(pb); /**< get size of the background frame */
    signature = avio_rb32(pb);
    avio_skip(pb, 4);         /* data size */
    frame_count = avio_rl32(pb);

    /* disallow back_sizes and frame_counts that may lead to overflows later */
    if(back_size > INT_MAX/2  || frame_count > INT_MAX / sizeof(uint32_t))
        return AVERROR_INVALIDDATA;

    avio_skip(pb, 2);         /* encoding mentod */
    sound_rate = avio_rl16(pb);
    rate = avio_rl16(pb);
    channels = avio_rl16(pb);
    def_sound_size = avio_rl16(pb);

    /** setup video stream */
    st = avformat_new_stream(s, NULL);
    if(!st)
         return AVERROR(ENOMEM);

    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
    st->codec->codec_id = CODEC_ID_RL2;
    st->codec->codec_tag = 0;  /* no fourcc */
    st->codec->width = 320;
    st->codec->height = 200;

    /** allocate and fill extradata */
    st->codec->extradata_size = EXTRADATA1_SIZE;

    if(signature == RLV3_TAG && back_size > 0)
        st->codec->extradata_size += back_size;

    st->codec->extradata = av_mallocz(st->codec->extradata_size +
                                          FF_INPUT_BUFFER_PADDING_SIZE);
    if(!st->codec->extradata)
        return AVERROR(ENOMEM);

    if(avio_read(pb,st->codec->extradata,st->codec->extradata_size) !=
                      st->codec->extradata_size)
        return AVERROR(EIO);

    /** setup audio stream if present */
    if(sound_rate){
        if(channels <= 0)
            return AVERROR_INVALIDDATA;

        pts_num = def_sound_size;
        pts_den = rate;

        st = avformat_new_stream(s, NULL);
        if (!st)
            return AVERROR(ENOMEM);
        st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
        st->codec->codec_id = CODEC_ID_PCM_U8;
        st->codec->codec_tag = 1;
        st->codec->channels = channels;
        st->codec->bits_per_coded_sample = 8;
        st->codec->sample_rate = rate;
        st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
            st->codec->bits_per_coded_sample;
        st->codec->block_align = st->codec->channels *
            st->codec->bits_per_coded_sample / 8;
        avpriv_set_pts_info(st,32,1,rate);
    }

    avpriv_set_pts_info(s->streams[0], 32, pts_num, pts_den);

    chunk_size =   av_malloc(frame_count * sizeof(uint32_t));
    audio_size =   av_malloc(frame_count * sizeof(uint32_t));
    chunk_offset = av_malloc(frame_count * sizeof(uint32_t));

    if(!chunk_size || !audio_size || !chunk_offset){
        av_free(chunk_size);
        av_free(audio_size);
        av_free(chunk_offset);
        return AVERROR(ENOMEM);
    }

    /** read offset and size tables */
    for(i=0; i < frame_count;i++)
        chunk_size[i] = avio_rl32(pb);
    for(i=0; i < frame_count;i++)
        chunk_offset[i] = avio_rl32(pb);
    for(i=0; i < frame_count;i++)
        audio_size[i] = avio_rl32(pb) & 0xFFFF;

    /** build the sample index */
    for(i=0;i<frame_count;i++){
        if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
            ret = AVERROR_INVALIDDATA;
            break;
        }

        if(sound_rate && audio_size[i]){
            av_add_index_entry(s->streams[1], chunk_offset[i],
                audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
            audio_frame_counter += audio_size[i] / channels;
        }
        av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
            video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
        ++video_frame_counter;
    }


    av_free(chunk_size);
    av_free(audio_size);
    av_free(chunk_offset);

    return ret;
}

/**
 * read a single audio or video packet
 * @param s demuxer context
 * @param pkt the packet to be filled
 * @return 0 on success, AVERROR otherwise
 */
static int rl2_read_packet(AVFormatContext *s,
                            AVPacket *pkt)
{
    Rl2DemuxContext *rl2 = s->priv_data;
    AVIOContext *pb = s->pb;
    AVIndexEntry *sample = NULL;
    int i;
    int ret = 0;
    int stream_id = -1;
    int64_t pos = INT64_MAX;

    /** check if there is a valid video or audio entry that can be used */
    for(i=0; i<s->nb_streams; i++){
        if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
              && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
            sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
            pos= sample->pos;
            stream_id= i;
        }
    }

    if(stream_id == -1)
        return AVERROR(EIO);

    ++rl2->index_pos[stream_id];

    /** position the stream (will probably be there anyway) */
    avio_seek(pb, sample->pos, SEEK_SET);

    /** fill the packet */
    ret = av_get_packet(pb, pkt, sample->size);
    if(ret != sample->size){
        av_free_packet(pkt);
        return AVERROR(EIO);
    }

    pkt->stream_index = stream_id;
    pkt->pts = sample->timestamp;

    return ret;
}

/**
 * seek to a new timestamp
 * @param s demuxer context
 * @param stream_index index of the stream that should be seeked
 * @param timestamp wanted timestamp
 * @param flags direction and seeking mode
 * @return 0 on success, -1 otherwise
 */
static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
{
    AVStream *st = s->streams[stream_index];
    Rl2DemuxContext *rl2 = s->priv_data;
    int i;
    int index = av_index_search_timestamp(st, timestamp, flags);
    if(index < 0)
        return -1;

    rl2->index_pos[stream_index] = index;
    timestamp = st->index_entries[index].timestamp;

    for(i=0; i < s->nb_streams; i++){
        AVStream *st2 = s->streams[i];
        index = av_index_search_timestamp(st2,
                    av_rescale_q(timestamp, st->time_base, st2->time_base),
                    flags | AVSEEK_FLAG_BACKWARD);

        if(index < 0)
            index = 0;

        rl2->index_pos[i] = index;
    }

    return 0;
}

AVInputFormat ff_rl2_demuxer = {
    .name           = "rl2",
    .long_name      = NULL_IF_CONFIG_SMALL("RL2 format"),
    .priv_data_size = sizeof(Rl2DemuxContext),
    .read_probe     = rl2_probe,
    .read_header    = rl2_read_header,
    .read_packet    = rl2_read_packet,
    .read_seek      = rl2_read_seek,
};
OpenPOWER on IntegriCloud