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 28typedef 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 37static 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 47static 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 138static 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 206AVInputFormat 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}; 214