Libav
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00001 /* 00002 * DXA demuxer 00003 * Copyright (c) 2007 Konstantin Shishkov 00004 * 00005 * This file is part of FFmpeg. 00006 * 00007 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 ByteIOContext *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 00064 tag = get_le32(pb); 00065 if (tag != MKTAG('D', 'E', 'X', 'A')) 00066 return -1; 00067 flags = get_byte(pb); 00068 c->frames = get_be16(pb); 00069 if(!c->frames){ 00070 av_log(s, AV_LOG_ERROR, "File contains no frames ???\n"); 00071 return -1; 00072 } 00073 00074 fps = get_be32(pb); 00075 if(fps > 0){ 00076 den = 1000; 00077 num = fps; 00078 }else if (fps < 0){ 00079 den = 100000; 00080 num = -fps; 00081 }else{ 00082 den = 10; 00083 num = 1; 00084 } 00085 w = get_be16(pb); 00086 h = get_be16(pb); 00087 c->has_sound = 0; 00088 00089 st = av_new_stream(s, 0); 00090 if (!st) 00091 return -1; 00092 00093 // Parse WAV data header 00094 if(get_le32(pb) == MKTAG('W', 'A', 'V', 'E')){ 00095 uint32_t size, fsize; 00096 c->has_sound = 1; 00097 size = get_be32(pb); 00098 c->vidpos = url_ftell(pb) + size; 00099 url_fskip(pb, 16); 00100 fsize = get_le32(pb); 00101 00102 ast = av_new_stream(s, 0); 00103 if (!ast) 00104 return -1; 00105 ff_get_wav_header(pb, ast->codec, fsize); 00106 // find 'data' chunk 00107 while(url_ftell(pb) < c->vidpos && !url_feof(pb)){ 00108 tag = get_le32(pb); 00109 fsize = get_le32(pb); 00110 if(tag == MKTAG('d', 'a', 't', 'a')) break; 00111 url_fskip(pb, fsize); 00112 } 00113 c->bpc = (fsize + c->frames - 1) / c->frames; 00114 if(ast->codec->block_align) 00115 c->bpc = ((c->bpc + ast->codec->block_align - 1) / ast->codec->block_align) * ast->codec->block_align; 00116 c->bytes_left = fsize; 00117 c->wavpos = url_ftell(pb); 00118 url_fseek(pb, c->vidpos, SEEK_SET); 00119 } 00120 00121 /* now we are ready: build format streams */ 00122 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00123 st->codec->codec_id = CODEC_ID_DXA; 00124 st->codec->width = w; 00125 st->codec->height = h; 00126 av_reduce(&den, &num, den, num, (1UL<<31)-1); 00127 av_set_pts_info(st, 33, num, den); 00128 /* flags & 0x80 means that image is interlaced, 00129 * flags & 0x40 means that image has double height 00130 * either way set true height 00131 */ 00132 if(flags & 0xC0){ 00133 st->codec->height >>= 1; 00134 } 00135 c->readvid = !c->has_sound; 00136 c->vidpos = url_ftell(pb); 00137 s->start_time = 0; 00138 s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den; 00139 av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames); 00140 00141 return 0; 00142 } 00143 00144 static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt) 00145 { 00146 DXAContext *c = s->priv_data; 00147 int ret; 00148 uint32_t size; 00149 uint8_t buf[DXA_EXTRA_SIZE], pal[768+4]; 00150 int pal_size = 0; 00151 00152 if(!c->readvid && c->has_sound && c->bytes_left){ 00153 c->readvid = 1; 00154 url_fseek(s->pb, c->wavpos, SEEK_SET); 00155 size = FFMIN(c->bytes_left, c->bpc); 00156 ret = av_get_packet(s->pb, pkt, size); 00157 pkt->stream_index = 1; 00158 if(ret != size) 00159 return AVERROR(EIO); 00160 c->bytes_left -= size; 00161 c->wavpos = url_ftell(s->pb); 00162 return 0; 00163 } 00164 url_fseek(s->pb, c->vidpos, SEEK_SET); 00165 while(!url_feof(s->pb) && c->frames){ 00166 get_buffer(s->pb, buf, 4); 00167 switch(AV_RL32(buf)){ 00168 case MKTAG('N', 'U', 'L', 'L'): 00169 if(av_new_packet(pkt, 4 + pal_size) < 0) 00170 return AVERROR(ENOMEM); 00171 pkt->stream_index = 0; 00172 if(pal_size) memcpy(pkt->data, pal, pal_size); 00173 memcpy(pkt->data + pal_size, buf, 4); 00174 c->frames--; 00175 c->vidpos = url_ftell(s->pb); 00176 c->readvid = 0; 00177 return 0; 00178 case MKTAG('C', 'M', 'A', 'P'): 00179 pal_size = 768+4; 00180 memcpy(pal, buf, 4); 00181 get_buffer(s->pb, pal + 4, 768); 00182 break; 00183 case MKTAG('F', 'R', 'A', 'M'): 00184 get_buffer(s->pb, buf + 4, DXA_EXTRA_SIZE - 4); 00185 size = AV_RB32(buf + 5); 00186 if(size > 0xFFFFFF){ 00187 av_log(s, AV_LOG_ERROR, "Frame size is too big: %d\n", size); 00188 return -1; 00189 } 00190 if(av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size) < 0) 00191 return AVERROR(ENOMEM); 00192 memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE); 00193 ret = get_buffer(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size); 00194 if(ret != size){ 00195 av_free_packet(pkt); 00196 return AVERROR(EIO); 00197 } 00198 if(pal_size) memcpy(pkt->data, pal, pal_size); 00199 pkt->stream_index = 0; 00200 c->frames--; 00201 c->vidpos = url_ftell(s->pb); 00202 c->readvid = 0; 00203 return 0; 00204 default: 00205 av_log(s, AV_LOG_ERROR, "Unknown tag %c%c%c%c\n", buf[0], buf[1], buf[2], buf[3]); 00206 return -1; 00207 } 00208 } 00209 return AVERROR(EIO); 00210 } 00211 00212 AVInputFormat dxa_demuxer = { 00213 "dxa", 00214 NULL_IF_CONFIG_SMALL("DXA"), 00215 sizeof(DXAContext), 00216 dxa_probe, 00217 dxa_read_header, 00218 dxa_read_packet, 00219 };