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 "internal.h"
25#include "riff.h"
26
27#define DXA_EXTRA_SIZE  9
28
29typedef struct{
30    int frames;
31    int has_sound;
32    int bpc;
33    uint32_t bytes_left;
34    int64_t wavpos, vidpos;
35    int readvid;
36}DXAContext;
37
38static int dxa_probe(AVProbeData *p)
39{
40    int w, h;
41    if (p->buf_size < 15)
42        return 0;
43    w = AV_RB16(p->buf + 11);
44    h = AV_RB16(p->buf + 13);
45    /* check file header */
46    if (p->buf[0] == 'D' && p->buf[1] == 'E' &&
47        p->buf[2] == 'X' && p->buf[3] == 'A' &&
48        w && w <= 2048 && h && h <= 2048)
49        return AVPROBE_SCORE_MAX;
50    else
51        return 0;
52}
53
54static int dxa_read_header(AVFormatContext *s, AVFormatParameters *ap)
55{
56    AVIOContext *pb = s->pb;
57    DXAContext *c = s->priv_data;
58    AVStream *st, *ast;
59    uint32_t tag;
60    int32_t fps;
61    int w, h;
62    int num, den;
63    int flags;
64    int ret;
65
66    tag = avio_rl32(pb);
67    if (tag != MKTAG('D', 'E', 'X', 'A'))
68        return -1;
69    flags = avio_r8(pb);
70    c->frames = avio_rb16(pb);
71    if(!c->frames){
72        av_log(s, AV_LOG_ERROR, "File contains no frames ???\n");
73        return -1;
74    }
75
76    fps = avio_rb32(pb);
77    if(fps > 0){
78        den = 1000;
79        num = fps;
80    }else if (fps < 0){
81        den = 100000;
82        num = -fps;
83    }else{
84        den = 10;
85        num = 1;
86    }
87    w = avio_rb16(pb);
88    h = avio_rb16(pb);
89    c->has_sound = 0;
90
91    st = avformat_new_stream(s, NULL);
92    if (!st)
93        return -1;
94
95    // Parse WAV data header
96    if(avio_rl32(pb) == MKTAG('W', 'A', 'V', 'E')){
97        uint32_t size, fsize;
98        c->has_sound = 1;
99        size = avio_rb32(pb);
100        c->vidpos = avio_tell(pb) + size;
101        avio_skip(pb, 16);
102        fsize = avio_rl32(pb);
103
104        ast = avformat_new_stream(s, NULL);
105        if (!ast)
106            return -1;
107        ret = ff_get_wav_header(pb, ast->codec, fsize);
108        if (ret < 0)
109            return ret;
110        // find 'data' chunk
111        while(avio_tell(pb) < c->vidpos && !pb->eof_reached){
112            tag = avio_rl32(pb);
113            fsize = avio_rl32(pb);
114            if(tag == MKTAG('d', 'a', 't', 'a')) break;
115            avio_skip(pb, fsize);
116        }
117        c->bpc = (fsize + c->frames - 1) / c->frames;
118        if(ast->codec->block_align)
119            c->bpc = ((c->bpc + ast->codec->block_align - 1) / ast->codec->block_align) * ast->codec->block_align;
120        c->bytes_left = fsize;
121        c->wavpos = avio_tell(pb);
122        avio_seek(pb, c->vidpos, SEEK_SET);
123    }
124
125    /* now we are ready: build format streams */
126    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
127    st->codec->codec_id   = CODEC_ID_DXA;
128    st->codec->width      = w;
129    st->codec->height     = h;
130    av_reduce(&den, &num, den, num, (1UL<<31)-1);
131    avpriv_set_pts_info(st, 33, num, den);
132    /* flags & 0x80 means that image is interlaced,
133     * flags & 0x40 means that image has double height
134     * either way set true height
135     */
136    if(flags & 0xC0){
137        st->codec->height >>= 1;
138    }
139    c->readvid = !c->has_sound;
140    c->vidpos  = avio_tell(pb);
141    s->start_time = 0;
142    s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den;
143    av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);
144
145    return 0;
146}
147
148static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt)
149{
150    DXAContext *c = s->priv_data;
151    int ret;
152    uint32_t size;
153    uint8_t buf[DXA_EXTRA_SIZE], pal[768+4];
154    int pal_size = 0;
155
156    if(!c->readvid && c->has_sound && c->bytes_left){
157        c->readvid = 1;
158        avio_seek(s->pb, c->wavpos, SEEK_SET);
159        size = FFMIN(c->bytes_left, c->bpc);
160        ret = av_get_packet(s->pb, pkt, size);
161        pkt->stream_index = 1;
162        if(ret != size)
163            return AVERROR(EIO);
164        c->bytes_left -= size;
165        c->wavpos = avio_tell(s->pb);
166        return 0;
167    }
168    avio_seek(s->pb, c->vidpos, SEEK_SET);
169    while(!s->pb->eof_reached && c->frames){
170        avio_read(s->pb, buf, 4);
171        switch(AV_RL32(buf)){
172        case MKTAG('N', 'U', 'L', 'L'):
173            if(av_new_packet(pkt, 4 + pal_size) < 0)
174                return AVERROR(ENOMEM);
175            pkt->stream_index = 0;
176            if(pal_size) memcpy(pkt->data, pal, pal_size);
177            memcpy(pkt->data + pal_size, buf, 4);
178            c->frames--;
179            c->vidpos = avio_tell(s->pb);
180            c->readvid = 0;
181            return 0;
182        case MKTAG('C', 'M', 'A', 'P'):
183            pal_size = 768+4;
184            memcpy(pal, buf, 4);
185            avio_read(s->pb, pal + 4, 768);
186            break;
187        case MKTAG('F', 'R', 'A', 'M'):
188            avio_read(s->pb, buf + 4, DXA_EXTRA_SIZE - 4);
189            size = AV_RB32(buf + 5);
190            if(size > 0xFFFFFF){
191                av_log(s, AV_LOG_ERROR, "Frame size is too big: %d\n", size);
192                return -1;
193            }
194            if(av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size) < 0)
195                return AVERROR(ENOMEM);
196            memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE);
197            ret = avio_read(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size);
198            if(ret != size){
199                av_free_packet(pkt);
200                return AVERROR(EIO);
201            }
202            if(pal_size) memcpy(pkt->data, pal, pal_size);
203            pkt->stream_index = 0;
204            c->frames--;
205            c->vidpos = avio_tell(s->pb);
206            c->readvid = 0;
207            return 0;
208        default:
209            av_log(s, AV_LOG_ERROR, "Unknown tag %c%c%c%c\n", buf[0], buf[1], buf[2], buf[3]);
210            return -1;
211        }
212    }
213    return AVERROR(EIO);
214}
215
216AVInputFormat ff_dxa_demuxer = {
217    .name           = "dxa",
218    .long_name      = NULL_IF_CONFIG_SMALL("DXA"),
219    .priv_data_size = sizeof(DXAContext),
220    .read_probe     = dxa_probe,
221    .read_header    = dxa_read_header,
222    .read_packet    = dxa_read_packet,
223};
224