Statistics
| Branch: | Revision:

ffmpeg / libavformat / dxa.c @ ca402f32

History | View | Annotate | Download (6.42 KB)

1
/*
2
 * DXA demuxer
3
 * Copyright (c) 2007 Konstantin Shishkov
4
 *
5
 * This file is part of Libav.
6
 *
7
 * Libav 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
 * Libav 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 Libav; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21

    
22
#include "libavutil/intreadwrite.h"
23
#include "avformat.h"
24
#include "riff.h"
25

    
26
#define DXA_EXTRA_SIZE  9
27

    
28
typedef struct{
29
    int frames;
30
    int has_sound;
31
    int bpc;
32
    uint32_t bytes_left;
33
    int64_t wavpos, vidpos;
34
    int readvid;
35
}DXAContext;
36

    
37
static int dxa_probe(AVProbeData *p)
38
{
39
    int w, h;
40
    if (p->buf_size < 15)
41
        return 0;
42
    w = AV_RB16(p->buf + 11);
43
    h = AV_RB16(p->buf + 13);
44
    /* check file header */
45
    if (p->buf[0] == 'D' && p->buf[1] == 'E' &&
46
        p->buf[2] == 'X' && p->buf[3] == 'A' &&
47
        w && w <= 2048 && h && h <= 2048)
48
        return AVPROBE_SCORE_MAX;
49
    else
50
        return 0;
51
}
52

    
53
static int dxa_read_header(AVFormatContext *s, AVFormatParameters *ap)
54
{
55
    AVIOContext *pb = s->pb;
56
    DXAContext *c = s->priv_data;
57
    AVStream *st, *ast;
58
    uint32_t tag;
59
    int32_t fps;
60
    int w, h;
61
    int num, den;
62
    int flags;
63
    int ret;
64

    
65
    tag = avio_rl32(pb);
66
    if (tag != MKTAG('D', 'E', 'X', 'A'))
67
        return -1;
68
    flags = avio_r8(pb);
69
    c->frames = avio_rb16(pb);
70
    if(!c->frames){
71
        av_log(s, AV_LOG_ERROR, "File contains no frames ???\n");
72
        return -1;
73
    }
74

    
75
    fps = avio_rb32(pb);
76
    if(fps > 0){
77
        den = 1000;
78
        num = fps;
79
    }else if (fps < 0){
80
        den = 100000;
81
        num = -fps;
82
    }else{
83
        den = 10;
84
        num = 1;
85
    }
86
    w = avio_rb16(pb);
87
    h = avio_rb16(pb);
88
    c->has_sound = 0;
89

    
90
    st = av_new_stream(s, 0);
91
    if (!st)
92
        return -1;
93

    
94
    // Parse WAV data header
95
    if(avio_rl32(pb) == MKTAG('W', 'A', 'V', 'E')){
96
        uint32_t size, fsize;
97
        c->has_sound = 1;
98
        size = avio_rb32(pb);
99
        c->vidpos = avio_tell(pb) + size;
100
        avio_skip(pb, 16);
101
        fsize = avio_rl32(pb);
102

    
103
        ast = av_new_stream(s, 0);
104
        if (!ast)
105
            return -1;
106
        ret = ff_get_wav_header(pb, ast->codec, fsize);
107
        if (ret < 0)
108
            return ret;
109
        // find 'data' chunk
110
        while(avio_tell(pb) < c->vidpos && !pb->eof_reached){
111
            tag = avio_rl32(pb);
112
            fsize = avio_rl32(pb);
113
            if(tag == MKTAG('d', 'a', 't', 'a')) break;
114
            avio_skip(pb, fsize);
115
        }
116
        c->bpc = (fsize + c->frames - 1) / c->frames;
117
        if(ast->codec->block_align)
118
            c->bpc = ((c->bpc + ast->codec->block_align - 1) / ast->codec->block_align) * ast->codec->block_align;
119
        c->bytes_left = fsize;
120
        c->wavpos = avio_tell(pb);
121
        avio_seek(pb, c->vidpos, SEEK_SET);
122
    }
123

    
124
    /* now we are ready: build format streams */
125
    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
126
    st->codec->codec_id   = CODEC_ID_DXA;
127
    st->codec->width      = w;
128
    st->codec->height     = h;
129
    av_reduce(&den, &num, den, num, (1UL<<31)-1);
130
    av_set_pts_info(st, 33, num, den);
131
    /* flags & 0x80 means that image is interlaced,
132
     * flags & 0x40 means that image has double height
133
     * either way set true height
134
     */
135
    if(flags & 0xC0){
136
        st->codec->height >>= 1;
137
    }
138
    c->readvid = !c->has_sound;
139
    c->vidpos  = avio_tell(pb);
140
    s->start_time = 0;
141
    s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den;
142
    av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);
143

    
144
    return 0;
145
}
146

    
147
static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt)
148
{
149
    DXAContext *c = s->priv_data;
150
    int ret;
151
    uint32_t size;
152
    uint8_t buf[DXA_EXTRA_SIZE], pal[768+4];
153
    int pal_size = 0;
154

    
155
    if(!c->readvid && c->has_sound && c->bytes_left){
156
        c->readvid = 1;
157
        avio_seek(s->pb, c->wavpos, SEEK_SET);
158
        size = FFMIN(c->bytes_left, c->bpc);
159
        ret = av_get_packet(s->pb, pkt, size);
160
        pkt->stream_index = 1;
161
        if(ret != size)
162
            return AVERROR(EIO);
163
        c->bytes_left -= size;
164
        c->wavpos = avio_tell(s->pb);
165
        return 0;
166
    }
167
    avio_seek(s->pb, c->vidpos, SEEK_SET);
168
    while(!s->pb->eof_reached && c->frames){
169
        avio_read(s->pb, buf, 4);
170
        switch(AV_RL32(buf)){
171
        case MKTAG('N', 'U', 'L', 'L'):
172
            if(av_new_packet(pkt, 4 + pal_size) < 0)
173
                return AVERROR(ENOMEM);
174
            pkt->stream_index = 0;
175
            if(pal_size) memcpy(pkt->data, pal, pal_size);
176
            memcpy(pkt->data + pal_size, buf, 4);
177
            c->frames--;
178
            c->vidpos = avio_tell(s->pb);
179
            c->readvid = 0;
180
            return 0;
181
        case MKTAG('C', 'M', 'A', 'P'):
182
            pal_size = 768+4;
183
            memcpy(pal, buf, 4);
184
            avio_read(s->pb, pal + 4, 768);
185
            break;
186
        case MKTAG('F', 'R', 'A', 'M'):
187
            avio_read(s->pb, buf + 4, DXA_EXTRA_SIZE - 4);
188
            size = AV_RB32(buf + 5);
189
            if(size > 0xFFFFFF){
190
                av_log(s, AV_LOG_ERROR, "Frame size is too big: %d\n", size);
191
                return -1;
192
            }
193
            if(av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size) < 0)
194
                return AVERROR(ENOMEM);
195
            memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE);
196
            ret = avio_read(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size);
197
            if(ret != size){
198
                av_free_packet(pkt);
199
                return AVERROR(EIO);
200
            }
201
            if(pal_size) memcpy(pkt->data, pal, pal_size);
202
            pkt->stream_index = 0;
203
            c->frames--;
204
            c->vidpos = avio_tell(s->pb);
205
            c->readvid = 0;
206
            return 0;
207
        default:
208
            av_log(s, AV_LOG_ERROR, "Unknown tag %c%c%c%c\n", buf[0], buf[1], buf[2], buf[3]);
209
            return -1;
210
        }
211
    }
212
    return AVERROR(EIO);
213
}
214

    
215
AVInputFormat ff_dxa_demuxer = {
216
    "dxa",
217
    NULL_IF_CONFIG_SMALL("DXA"),
218
    sizeof(DXAContext),
219
    dxa_probe,
220
    dxa_read_header,
221
    dxa_read_packet,
222
};