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     /* check file header */
  40     if (p->buf[0] == 'D' && p->buf[1] == 'E' &&
  41         p->buf[2] == 'X' && p->buf[3] == 'A')
  42         return AVPROBE_SCORE_MAX;
  43     else
  44         return 0;
  45 }
  46
  47 static int dxa_read_header(AVFormatContext *s, AVFormatParameters *ap)
  48 {
  49     ByteIOContext *pb = s->pb;
  50     DXAContext *c = s->priv_data;
  51     AVStream *st, *ast;
  52     uint32_t tag;
  53     int32_t fps;
  54     int w, h;
  55     int num, den;
  56     int flags;
  57
  58     tag = get_le32(pb);
  59     if (tag != MKTAG('D', 'E', 'X', 'A'))
  60         return -1;
  61     flags = get_byte(pb);
  62     c->frames = get_be16(pb);
  63     if(!c->frames){
  64         av_log(s, AV_LOG_ERROR, "File contains no frames ???\n");
  65         return -1;
  66     }
  67
  68     fps = get_be32(pb);
  69     if(fps > 0){
  70         den = 1000;
  71         num = fps;
  72     }else if (fps < 0){
  73         den = 100000;
  74         num = -fps;
  75     }else{
  76         den = 10;
  77         num = 1;
  78     }
  79     w = get_be16(pb);
  80     h = get_be16(pb);
  81     c->has_sound = 0;
  82
  83     st = av_new_stream(s, 0);
  84     if (!st)
  85         return -1;
  86
  87     // Parse WAV data header
  88     if(get_le32(pb) == MKTAG('W', 'A', 'V', 'E')){
  89         uint32_t size, fsize;
  90         c->has_sound = 1;
  91         size = get_be32(pb);
  92         c->vidpos = url_ftell(pb) + size;
  93         url_fskip(pb, 16);
  94         fsize = get_le32(pb);
  95
  96         ast = av_new_stream(s, 0);
  97         if (!ast)
  98             return -1;
  99         get_wav_header(pb, ast->codec, fsize);
 100         // find 'data' chunk
 101         while(url_ftell(pb) < c->vidpos && !url_feof(pb)){
 102             tag = get_le32(pb);
 103             fsize = get_le32(pb);
 104             if(tag == MKTAG('d', 'a', 't', 'a')) break;
 105             url_fskip(pb, fsize);
 106         }
 107         c->bpc = (fsize + c->frames - 1) / c->frames;
 108         if(ast->codec->block_align)
 109             c->bpc = ((c->bpc + ast->codec->block_align - 1) / ast->codec->block_align) * ast->codec->block_align;
 110         c->bytes_left = fsize;
 111         c->wavpos = url_ftell(pb);
 112         url_fseek(pb, c->vidpos, SEEK_SET);
 113     }
 114
 115     /* now we are ready: build format streams */
 116     st->codec->codec_type = CODEC_TYPE_VIDEO;
 117     st->codec->codec_id   = CODEC_ID_DXA;
 118     st->codec->width      = w;
 119     st->codec->height     = h;
 120     av_reduce(&den, &num, den, num, (1UL<<31)-1);
 121     av_set_pts_info(st, 33, num, den);
 122     /* flags & 0x80 means that image is interlaced,
 123      * flags & 0x40 means that image has double height
 124      * either way set true height
 125      */
 126     if(flags & 0xC0){
 127         st->codec->height >>= 1;
 128     }
 129     c->readvid = !c->has_sound;
 130     c->vidpos  = url_ftell(pb);
 131     s->start_time = 0;
 132     s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den;
 133     av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);
 134
 135     return 0;
 136 }
 137
 138 static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt)
 139 {
 140     DXAContext *c = s->priv_data;
 141     int ret;
 142     uint32_t size;
 143     uint8_t buf[DXA_EXTRA_SIZE], pal[768+4];
 144     int pal_size = 0;
 145
 146     if(!c->readvid && c->has_sound && c->bytes_left){
 147         c->readvid = 1;
 148         url_fseek(s->pb, c->wavpos, SEEK_SET);
 149         size = FFMIN(c->bytes_left, c->bpc);
 150         ret = av_get_packet(s->pb, pkt, size);
 151         pkt->stream_index = 1;
 152         if(ret != size)
 153             return AVERROR(EIO);
 154         c->bytes_left -= size;
 155         c->wavpos = url_ftell(s->pb);
 156         return 0;
 157     }
 158     url_fseek(s->pb, c->vidpos, SEEK_SET);
 159     while(!url_feof(s->pb) && c->frames){
 160         get_buffer(s->pb, buf, 4);
 161         switch(AV_RL32(buf)){
 162         case MKTAG('N', 'U', 'L', 'L'):
 163             if(av_new_packet(pkt, 4 + pal_size) < 0)
 164                 return AVERROR(ENOMEM);
 165             pkt->stream_index = 0;
 166             if(pal_size) memcpy(pkt->data, pal, pal_size);
 167             memcpy(pkt->data + pal_size, buf, 4);
 168             c->frames--;
 169             c->vidpos = url_ftell(s->pb);
 170             c->readvid = 0;
 171             return 0;
 172         case MKTAG('C', 'M', 'A', 'P'):
 173             pal_size = 768+4;
 174             memcpy(pal, buf, 4);
 175             get_buffer(s->pb, pal + 4, 768);
 176             break;
 177         case MKTAG('F', 'R', 'A', 'M'):
 178             get_buffer(s->pb, buf + 4, DXA_EXTRA_SIZE - 4);
 179             size = AV_RB32(buf + 5);
 180             if(size > 0xFFFFFF){
 181                 av_log(s, AV_LOG_ERROR, "Frame size is too big: %d\n", size);
 182                 return -1;
 183             }
 184             if(av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size) < 0)
 185                 return AVERROR(ENOMEM);
 186             memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE);
 187             ret = get_buffer(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size);
 188             if(ret != size){
 189                 av_free_packet(pkt);
 190                 return AVERROR(EIO);
 191             }
 192             if(pal_size) memcpy(pkt->data, pal, pal_size);
 193             pkt->stream_index = 0;
 194             c->frames--;
 195             c->vidpos = url_ftell(s->pb);
 196             c->readvid = 0;
 197             return 0;
 198         default:
 199             av_log(s, AV_LOG_ERROR, "Unknown tag %c%c%c%c\n", buf[0], buf[1], buf[2], buf[3]);
 200             return -1;
 201         }
 202     }
 203     return AVERROR(EIO);
 204 }
 205
 206 AVInputFormat dxa_demuxer = {
 207     "dxa",
 208     NULL_IF_CONFIG_SMALL("DXA"),
 209     sizeof(DXAContext),
 210     dxa_probe,
 211     dxa_read_header,
 212     dxa_read_packet,
 213 };