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