Libav 0.7.1
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00001 /* 00002 * DXA demuxer 00003 * Copyright (c) 2007 Konstantin Shishkov 00004 * 00005 * This file is part of Libav. 00006 * 00007 * Libav is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * Libav is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with Libav; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00022 #include "libavutil/intreadwrite.h" 00023 #include "avformat.h" 00024 #include "riff.h" 00025 00026 #define DXA_EXTRA_SIZE 9 00027 00028 typedef struct{ 00029 int frames; 00030 int has_sound; 00031 int bpc; 00032 uint32_t bytes_left; 00033 int64_t wavpos, vidpos; 00034 int readvid; 00035 }DXAContext; 00036 00037 static int dxa_probe(AVProbeData *p) 00038 { 00039 int w, h; 00040 if (p->buf_size < 15) 00041 return 0; 00042 w = AV_RB16(p->buf + 11); 00043 h = AV_RB16(p->buf + 13); 00044 /* check file header */ 00045 if (p->buf[0] == 'D' && p->buf[1] == 'E' && 00046 p->buf[2] == 'X' && p->buf[3] == 'A' && 00047 w && w <= 2048 && h && h <= 2048) 00048 return AVPROBE_SCORE_MAX; 00049 else 00050 return 0; 00051 } 00052 00053 static int dxa_read_header(AVFormatContext *s, AVFormatParameters *ap) 00054 { 00055 AVIOContext *pb = s->pb; 00056 DXAContext *c = s->priv_data; 00057 AVStream *st, *ast; 00058 uint32_t tag; 00059 int32_t fps; 00060 int w, h; 00061 int num, den; 00062 int flags; 00063 int ret; 00064 00065 tag = avio_rl32(pb); 00066 if (tag != MKTAG('D', 'E', 'X', 'A')) 00067 return -1; 00068 flags = avio_r8(pb); 00069 c->frames = avio_rb16(pb); 00070 if(!c->frames){ 00071 av_log(s, AV_LOG_ERROR, "File contains no frames ???\n"); 00072 return -1; 00073 } 00074 00075 fps = avio_rb32(pb); 00076 if(fps > 0){ 00077 den = 1000; 00078 num = fps; 00079 }else if (fps < 0){ 00080 den = 100000; 00081 num = -fps; 00082 }else{ 00083 den = 10; 00084 num = 1; 00085 } 00086 w = avio_rb16(pb); 00087 h = avio_rb16(pb); 00088 c->has_sound = 0; 00089 00090 st = av_new_stream(s, 0); 00091 if (!st) 00092 return -1; 00093 00094 // Parse WAV data header 00095 if(avio_rl32(pb) == MKTAG('W', 'A', 'V', 'E')){ 00096 uint32_t size, fsize; 00097 c->has_sound = 1; 00098 size = avio_rb32(pb); 00099 c->vidpos = avio_tell(pb) + size; 00100 avio_skip(pb, 16); 00101 fsize = avio_rl32(pb); 00102 00103 ast = av_new_stream(s, 0); 00104 if (!ast) 00105 return -1; 00106 ret = ff_get_wav_header(pb, ast->codec, fsize); 00107 if (ret < 0) 00108 return ret; 00109 // find 'data' chunk 00110 while(avio_tell(pb) < c->vidpos && !pb->eof_reached){ 00111 tag = avio_rl32(pb); 00112 fsize = avio_rl32(pb); 00113 if(tag == MKTAG('d', 'a', 't', 'a')) break; 00114 avio_skip(pb, fsize); 00115 } 00116 c->bpc = (fsize + c->frames - 1) / c->frames; 00117 if(ast->codec->block_align) 00118 c->bpc = ((c->bpc + ast->codec->block_align - 1) / ast->codec->block_align) * ast->codec->block_align; 00119 c->bytes_left = fsize; 00120 c->wavpos = avio_tell(pb); 00121 avio_seek(pb, c->vidpos, SEEK_SET); 00122 } 00123 00124 /* now we are ready: build format streams */ 00125 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00126 st->codec->codec_id = CODEC_ID_DXA; 00127 st->codec->width = w; 00128 st->codec->height = h; 00129 av_reduce(&den, &num, den, num, (1UL<<31)-1); 00130 av_set_pts_info(st, 33, num, den); 00131 /* flags & 0x80 means that image is interlaced, 00132 * flags & 0x40 means that image has double height 00133 * either way set true height 00134 */ 00135 if(flags & 0xC0){ 00136 st->codec->height >>= 1; 00137 } 00138 c->readvid = !c->has_sound; 00139 c->vidpos = avio_tell(pb); 00140 s->start_time = 0; 00141 s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den; 00142 av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames); 00143 00144 return 0; 00145 } 00146 00147 static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt) 00148 { 00149 DXAContext *c = s->priv_data; 00150 int ret; 00151 uint32_t size; 00152 uint8_t buf[DXA_EXTRA_SIZE], pal[768+4]; 00153 int pal_size = 0; 00154 00155 if(!c->readvid && c->has_sound && c->bytes_left){ 00156 c->readvid = 1; 00157 avio_seek(s->pb, c->wavpos, SEEK_SET); 00158 size = FFMIN(c->bytes_left, c->bpc); 00159 ret = av_get_packet(s->pb, pkt, size); 00160 pkt->stream_index = 1; 00161 if(ret != size) 00162 return AVERROR(EIO); 00163 c->bytes_left -= size; 00164 c->wavpos = avio_tell(s->pb); 00165 return 0; 00166 } 00167 avio_seek(s->pb, c->vidpos, SEEK_SET); 00168 while(!s->pb->eof_reached && c->frames){ 00169 avio_read(s->pb, buf, 4); 00170 switch(AV_RL32(buf)){ 00171 case MKTAG('N', 'U', 'L', 'L'): 00172 if(av_new_packet(pkt, 4 + pal_size) < 0) 00173 return AVERROR(ENOMEM); 00174 pkt->stream_index = 0; 00175 if(pal_size) memcpy(pkt->data, pal, pal_size); 00176 memcpy(pkt->data + pal_size, buf, 4); 00177 c->frames--; 00178 c->vidpos = avio_tell(s->pb); 00179 c->readvid = 0; 00180 return 0; 00181 case MKTAG('C', 'M', 'A', 'P'): 00182 pal_size = 768+4; 00183 memcpy(pal, buf, 4); 00184 avio_read(s->pb, pal + 4, 768); 00185 break; 00186 case MKTAG('F', 'R', 'A', 'M'): 00187 avio_read(s->pb, buf + 4, DXA_EXTRA_SIZE - 4); 00188 size = AV_RB32(buf + 5); 00189 if(size > 0xFFFFFF){ 00190 av_log(s, AV_LOG_ERROR, "Frame size is too big: %d\n", size); 00191 return -1; 00192 } 00193 if(av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size) < 0) 00194 return AVERROR(ENOMEM); 00195 memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE); 00196 ret = avio_read(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size); 00197 if(ret != size){ 00198 av_free_packet(pkt); 00199 return AVERROR(EIO); 00200 } 00201 if(pal_size) memcpy(pkt->data, pal, pal_size); 00202 pkt->stream_index = 0; 00203 c->frames--; 00204 c->vidpos = avio_tell(s->pb); 00205 c->readvid = 0; 00206 return 0; 00207 default: 00208 av_log(s, AV_LOG_ERROR, "Unknown tag %c%c%c%c\n", buf[0], buf[1], buf[2], buf[3]); 00209 return -1; 00210 } 00211 } 00212 return AVERROR(EIO); 00213 } 00214 00215 AVInputFormat ff_dxa_demuxer = { 00216 "dxa", 00217 NULL_IF_CONFIG_SMALL("DXA"), 00218 sizeof(DXAContext), 00219 dxa_probe, 00220 dxa_read_header, 00221 dxa_read_packet, 00222 };