libavformat/dxa.c

   1 /*
   2  * DXA demuxer
   3  * Copyright (c) 2007 Konstantin Shishkov.
   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 #include "avformat.h"
  23 #include "riff.h"
  24
  25 #define DXA_EXTRA_SIZE  9
  26
  27 typedef struct{
  28     int frames;
  29     int has_sound;
  30     int bpc;
  31     uint32_t bytes_left;
  32     int64_t wavpos, vidpos;
  33     int readvid;
  34 }DXAContext;
  35
  36 static int dxa_probe(AVProbeData *p)
  37 {
  38     /* check file header */
  39     if (p->buf[0] == 'D' && p->buf[1] == 'E' &&
  40         p->buf[2] == 'X' && p->buf[3] == 'A')
  41         return AVPROBE_SCORE_MAX;
  42     else
  43         return 0;
  44 }
  45
  46 static int dxa_read_header(AVFormatContext *s, AVFormatParameters *ap)
  47 {
  48     ByteIOContext *pb = s->pb;
  49     DXAContext *c = s->priv_data;
  50     AVStream *st, *ast;
  51     uint32_t tag;
  52     int32_t fps;
  53     int w, h;
  54     int num, den;
  55     int flags;
  56
  57     tag = get_le32(pb);
  58     if (tag != MKTAG('D', 'E', 'X', 'A'))
  59         return -1;
  60     flags = get_byte(pb);
  61     c->frames = get_be16(pb);
  62     if(!c->frames){
  63         av_log(s, AV_LOG_ERROR, "File contains no frames ???\n");
  64         return -1;
  65     }
  66
  67     fps = get_be32(pb);
  68     if(fps > 0){
  69         den = 1000;
  70         num = fps;
  71     }else if (fps < 0){
  72         den = 100000;
  73         num = -fps;
  74     }else{
  75         den = 10;
  76         num = 1;
  77     }
  78     w = get_be16(pb);
  79     h = get_be16(pb);
  80     c->has_sound = 0;
  81
  82     st = av_new_stream(s, 0);
  83     if (!st)
  84         return -1;
  85
  86     // Parse WAV data header
  87     if(get_le32(pb) == MKTAG('W', 'A', 'V', 'E')){
  88         uint32_t size, fsize;
  89         c->has_sound = 1;
  90         size = get_be32(pb);
  91         c->vidpos = url_ftell(pb) + size;
  92         url_fskip(pb, 16);
  93         fsize = get_le32(pb);
  94
  95         ast = av_new_stream(s, 0);
  96         if (!ast)
  97             return -1;
  98         get_wav_header(pb, ast->codec, fsize);
  99         // find 'data' chunk
 100         while(url_ftell(pb) < c->vidpos && !url_feof(pb)){
 101             tag = get_le32(pb);
 102             fsize = get_le32(pb);
 103             if(tag == MKTAG('d', 'a', 't', 'a')) break;
 104             url_fskip(pb, fsize);
 105         }
 106         c->bpc = (fsize + c->frames - 1) / c->frames;
 107         if(ast->codec->block_align)
 108             c->bpc = ((c->bpc + ast->codec->block_align - 1) / ast->codec->block_align) * ast->codec->block_align;
 109         c->bytes_left = fsize;
 110         c->wavpos = url_ftell(pb);
 111         url_fseek(pb, c->vidpos, SEEK_SET);
 112     }
 113
 114     /* now we are ready: build format streams */
 115     st->codec->codec_type = CODEC_TYPE_VIDEO;
 116     st->codec->codec_id   = CODEC_ID_DXA;
 117     st->codec->width      = w;
 118     st->codec->height     = h;
 119     av_reduce(&den, &num, den, num, (1UL<<31)-1);
 120     av_set_pts_info(st, 33, num, den);
 121     /* flags & 0x80 means that image is interlaced,
 122      * flags & 0x40 means that image has double height
 123      * either way set true height
 124      */
 125     if(flags & 0xC0){
 126         st->codec->height >>= 1;
 127     }
 128     c->readvid = !c->has_sound;
 129     c->vidpos  = url_ftell(pb);
 130     s->start_time = 0;
 131     s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den;
 132     av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);
 133
 134     return 0;
 135 }
 136
 137 static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt)
 138 {
 139     DXAContext *c = s->priv_data;
 140     int ret;
 141     uint32_t size;
 142     uint8_t buf[DXA_EXTRA_SIZE], pal[768+4];
 143     int pal_size = 0;
 144
 145     if(!c->readvid && c->has_sound && c->bytes_left){
 146         c->readvid = 1;
 147         url_fseek(s->pb, c->wavpos, SEEK_SET);
 148         size = FFMIN(c->bytes_left, c->bpc);
 149         ret = av_get_packet(s->pb, pkt, size);
 150         pkt->stream_index = 1;
 151         if(ret != size)
 152             return AVERROR(EIO);
 153         c->bytes_left -= size;
 154         c->wavpos = url_ftell(s->pb);
 155         return 0;
 156     }
 157     url_fseek(s->pb, c->vidpos, SEEK_SET);
 158     while(!url_feof(s->pb) && c->frames){
 159         get_buffer(s->pb, buf, 4);
 160         switch(AV_RL32(buf)){
 161         case MKTAG('N', 'U', 'L', 'L'):
 162             if(av_new_packet(pkt, 4 + pal_size) < 0)
 163                 return AVERROR(ENOMEM);
 164             pkt->stream_index = 0;
 165             if(pal_size) memcpy(pkt->data, pal, pal_size);
 166             memcpy(pkt->data + pal_size, buf, 4);
 167             c->frames--;
 168             c->vidpos = url_ftell(s->pb);
 169             c->readvid = 0;
 170             return 0;
 171         case MKTAG('C', 'M', 'A', 'P'):
 172             pal_size = 768+4;
 173             memcpy(pal, buf, 4);
 174             get_buffer(s->pb, pal + 4, 768);
 175             break;
 176         case MKTAG('F', 'R', 'A', 'M'):
 177             get_buffer(s->pb, buf + 4, DXA_EXTRA_SIZE - 4);
 178             size = AV_RB32(buf + 5);
 179             if(size > 0xFFFFFF){
 180                 av_log(s, AV_LOG_ERROR, "Frame size is too big: %d\n", size);
 181                 return -1;
 182             }
 183             if(av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size) < 0)
 184                 return AVERROR(ENOMEM);
 185             memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE);
 186             ret = get_buffer(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size);
 187             if(ret != size){
 188                 av_free_packet(pkt);
 189                 return AVERROR(EIO);
 190             }
 191             if(pal_size) memcpy(pkt->data, pal, pal_size);
 192             pkt->stream_index = 0;
 193             c->frames--;
 194             c->vidpos = url_ftell(s->pb);
 195             c->readvid = 0;
 196             return 0;
 197         default:
 198             av_log(s, AV_LOG_ERROR, "Unknown tag %c%c%c%c\n", buf[0], buf[1], buf[2], buf[3]);
 199             return -1;
 200         }
 201     }
 202     return AVERROR(EIO);
 203 }
 204
 205 AVInputFormat dxa_demuxer = {
 206     "dxa",
 207     NULL_IF_CONFIG_SMALL("DXA"),
 208     sizeof(DXAContext),
 209     dxa_probe,
 210     dxa_read_header,
 211     dxa_read_packet,
 212 };