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 "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     ByteIOContext *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
  64     tag = get_le32(pb);
  65     if (tag != MKTAG('D', 'E', 'X', 'A'))
  66         return -1;
  67     flags = get_byte(pb);
  68     c->frames = get_be16(pb);
  69     if(!c->frames){
  70         av_log(s, AV_LOG_ERROR, "File contains no frames ???\n");
  71         return -1;
  72     }
  73
  74     fps = get_be32(pb);
  75     if(fps > 0){
  76         den = 1000;
  77         num = fps;
  78     }else if (fps < 0){
  79         den = 100000;
  80         num = -fps;
  81     }else{
  82         den = 10;
  83         num = 1;
  84     }
  85     w = get_be16(pb);
  86     h = get_be16(pb);
  87     c->has_sound = 0;
  88
  89     st = av_new_stream(s, 0);
  90     if (!st)
  91         return -1;
  92
  93     // Parse WAV data header
  94     if(get_le32(pb) == MKTAG('W', 'A', 'V', 'E')){
  95         uint32_t size, fsize;
  96         c->has_sound = 1;
  97         size = get_be32(pb);
  98         c->vidpos = url_ftell(pb) + size;
  99         url_fskip(pb, 16);
 100         fsize = get_le32(pb);
 101
 102         ast = av_new_stream(s, 0);
 103         if (!ast)
 104             return -1;
 105         ff_get_wav_header(pb, ast->codec, fsize);
 106         // find 'data' chunk
 107         while(url_ftell(pb) < c->vidpos && !url_feof(pb)){
 108             tag = get_le32(pb);
 109             fsize = get_le32(pb);
 110             if(tag == MKTAG('d', 'a', 't', 'a')) break;
 111             url_fskip(pb, fsize);
 112         }
 113         c->bpc = (fsize + c->frames - 1) / c->frames;
 114         if(ast->codec->block_align)
 115             c->bpc = ((c->bpc + ast->codec->block_align - 1) / ast->codec->block_align) * ast->codec->block_align;
 116         c->bytes_left = fsize;
 117         c->wavpos = url_ftell(pb);
 118         url_fseek(pb, c->vidpos, SEEK_SET);
 119     }
 120
 121     /* now we are ready: build format streams */
 122     st->codec->codec_type = CODEC_TYPE_VIDEO;
 123     st->codec->codec_id   = CODEC_ID_DXA;
 124     st->codec->width      = w;
 125     st->codec->height     = h;
 126     av_reduce(&den, &num, den, num, (1UL<<31)-1);
 127     av_set_pts_info(st, 33, num, den);
 128     /* flags & 0x80 means that image is interlaced,
 129      * flags & 0x40 means that image has double height
 130      * either way set true height
 131      */
 132     if(flags & 0xC0){
 133         st->codec->height >>= 1;
 134     }
 135     c->readvid = !c->has_sound;
 136     c->vidpos  = url_ftell(pb);
 137     s->start_time = 0;
 138     s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den;
 139     av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);
 140
 141     return 0;
 142 }
 143
 144 static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt)
 145 {
 146     DXAContext *c = s->priv_data;
 147     int ret;
 148     uint32_t size;
 149     uint8_t buf[DXA_EXTRA_SIZE], pal[768+4];
 150     int pal_size = 0;
 151
 152     if(!c->readvid && c->has_sound && c->bytes_left){
 153         c->readvid = 1;
 154         url_fseek(s->pb, c->wavpos, SEEK_SET);
 155         size = FFMIN(c->bytes_left, c->bpc);
 156         ret = av_get_packet(s->pb, pkt, size);
 157         pkt->stream_index = 1;
 158         if(ret != size)
 159             return AVERROR(EIO);
 160         c->bytes_left -= size;
 161         c->wavpos = url_ftell(s->pb);
 162         return 0;
 163     }
 164     url_fseek(s->pb, c->vidpos, SEEK_SET);
 165     while(!url_feof(s->pb) && c->frames){
 166         get_buffer(s->pb, buf, 4);
 167         switch(AV_RL32(buf)){
 168         case MKTAG('N', 'U', 'L', 'L'):
 169             if(av_new_packet(pkt, 4 + pal_size) < 0)
 170                 return AVERROR(ENOMEM);
 171             pkt->stream_index = 0;
 172             if(pal_size) memcpy(pkt->data, pal, pal_size);
 173             memcpy(pkt->data + pal_size, buf, 4);
 174             c->frames--;
 175             c->vidpos = url_ftell(s->pb);
 176             c->readvid = 0;
 177             return 0;
 178         case MKTAG('C', 'M', 'A', 'P'):
 179             pal_size = 768+4;
 180             memcpy(pal, buf, 4);
 181             get_buffer(s->pb, pal + 4, 768);
 182             break;
 183         case MKTAG('F', 'R', 'A', 'M'):
 184             get_buffer(s->pb, buf + 4, DXA_EXTRA_SIZE - 4);
 185             size = AV_RB32(buf + 5);
 186             if(size > 0xFFFFFF){
 187                 av_log(s, AV_LOG_ERROR, "Frame size is too big: %d\n", size);
 188                 return -1;
 189             }
 190             if(av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size) < 0)
 191                 return AVERROR(ENOMEM);
 192             memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE);
 193             ret = get_buffer(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size);
 194             if(ret != size){
 195                 av_free_packet(pkt);
 196                 return AVERROR(EIO);
 197             }
 198             if(pal_size) memcpy(pkt->data, pal, pal_size);
 199             pkt->stream_index = 0;
 200             c->frames--;
 201             c->vidpos = url_ftell(s->pb);
 202             c->readvid = 0;
 203             return 0;
 204         default:
 205             av_log(s, AV_LOG_ERROR, "Unknown tag %c%c%c%c\n", buf[0], buf[1], buf[2], buf[3]);
 206             return -1;
 207         }
 208     }
 209     return AVERROR(EIO);
 210 }
 211
 212 AVInputFormat dxa_demuxer = {
 213     "dxa",
 214     NULL_IF_CONFIG_SMALL("DXA"),
 215     sizeof(DXAContext),
 216     dxa_probe,
 217     dxa_read_header,
 218     dxa_read_packet,
 219 };