Libav 0.7.1
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00001 /* 00002 * Flash Compatible Streaming Format demuxer 00003 * Copyright (c) 2000 Fabrice Bellard 00004 * Copyright (c) 2003 Tinic Uro 00005 * 00006 * This file is part of Libav. 00007 * 00008 * Libav is free software; you can redistribute it and/or 00009 * modify it under the terms of the GNU Lesser General Public 00010 * License as published by the Free Software Foundation; either 00011 * version 2.1 of the License, or (at your option) any later version. 00012 * 00013 * Libav is distributed in the hope that it will be useful, 00014 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00016 * Lesser General Public License for more details. 00017 * 00018 * You should have received a copy of the GNU Lesser General Public 00019 * License along with Libav; if not, write to the Free Software 00020 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00021 */ 00022 00023 #include "libavutil/intreadwrite.h" 00024 #include "swf.h" 00025 00026 static int get_swf_tag(AVIOContext *pb, int *len_ptr) 00027 { 00028 int tag, len; 00029 00030 if (pb->eof_reached) 00031 return -1; 00032 00033 tag = avio_rl16(pb); 00034 len = tag & 0x3f; 00035 tag = tag >> 6; 00036 if (len == 0x3f) { 00037 len = avio_rl32(pb); 00038 } 00039 // av_log(NULL, AV_LOG_DEBUG, "Tag: %d - Len: %d\n", tag, len); 00040 *len_ptr = len; 00041 return tag; 00042 } 00043 00044 00045 static int swf_probe(AVProbeData *p) 00046 { 00047 /* check file header */ 00048 if ((p->buf[0] == 'F' || p->buf[0] == 'C') && p->buf[1] == 'W' && 00049 p->buf[2] == 'S') 00050 return AVPROBE_SCORE_MAX; 00051 else 00052 return 0; 00053 } 00054 00055 static int swf_read_header(AVFormatContext *s, AVFormatParameters *ap) 00056 { 00057 SWFContext *swf = s->priv_data; 00058 AVIOContext *pb = s->pb; 00059 int nbits, len, tag; 00060 00061 tag = avio_rb32(pb) & 0xffffff00; 00062 00063 if (tag == MKBETAG('C', 'W', 'S', 0)) { 00064 av_log(s, AV_LOG_ERROR, "Compressed SWF format not supported\n"); 00065 return AVERROR(EIO); 00066 } 00067 if (tag != MKBETAG('F', 'W', 'S', 0)) 00068 return AVERROR(EIO); 00069 avio_rl32(pb); 00070 /* skip rectangle size */ 00071 nbits = avio_r8(pb) >> 3; 00072 len = (4 * nbits - 3 + 7) / 8; 00073 avio_skip(pb, len); 00074 swf->frame_rate = avio_rl16(pb); /* 8.8 fixed */ 00075 avio_rl16(pb); /* frame count */ 00076 00077 swf->samples_per_frame = 0; 00078 s->ctx_flags |= AVFMTCTX_NOHEADER; 00079 return 0; 00080 } 00081 00082 static int swf_read_packet(AVFormatContext *s, AVPacket *pkt) 00083 { 00084 SWFContext *swf = s->priv_data; 00085 AVIOContext *pb = s->pb; 00086 AVStream *vst = NULL, *ast = NULL, *st = 0; 00087 int tag, len, i, frame, v, res; 00088 00089 for(;;) { 00090 uint64_t pos = avio_tell(pb); 00091 tag = get_swf_tag(pb, &len); 00092 if (tag < 0) 00093 return AVERROR(EIO); 00094 if (tag == TAG_VIDEOSTREAM) { 00095 int ch_id = avio_rl16(pb); 00096 len -= 2; 00097 00098 for (i=0; i<s->nb_streams; i++) { 00099 st = s->streams[i]; 00100 if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && st->id == ch_id) 00101 goto skip; 00102 } 00103 00104 avio_rl16(pb); 00105 avio_rl16(pb); 00106 avio_rl16(pb); 00107 avio_r8(pb); 00108 /* Check for FLV1 */ 00109 vst = av_new_stream(s, ch_id); 00110 if (!vst) 00111 return -1; 00112 vst->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00113 vst->codec->codec_id = ff_codec_get_id(swf_codec_tags, avio_r8(pb)); 00114 av_set_pts_info(vst, 16, 256, swf->frame_rate); 00115 vst->codec->time_base = (AVRational){ 256, swf->frame_rate }; 00116 len -= 8; 00117 } else if (tag == TAG_STREAMHEAD || tag == TAG_STREAMHEAD2) { 00118 /* streaming found */ 00119 int sample_rate_code; 00120 00121 for (i=0; i<s->nb_streams; i++) { 00122 st = s->streams[i]; 00123 if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO && st->id == -1) 00124 goto skip; 00125 } 00126 00127 avio_r8(pb); 00128 v = avio_r8(pb); 00129 swf->samples_per_frame = avio_rl16(pb); 00130 ast = av_new_stream(s, -1); /* -1 to avoid clash with video stream ch_id */ 00131 if (!ast) 00132 return -1; 00133 ast->codec->channels = 1 + (v&1); 00134 ast->codec->codec_type = AVMEDIA_TYPE_AUDIO; 00135 ast->codec->codec_id = ff_codec_get_id(swf_audio_codec_tags, (v>>4) & 15); 00136 ast->need_parsing = AVSTREAM_PARSE_FULL; 00137 sample_rate_code= (v>>2) & 3; 00138 if (!sample_rate_code) 00139 return AVERROR(EIO); 00140 ast->codec->sample_rate = 11025 << (sample_rate_code-1); 00141 av_set_pts_info(ast, 64, 1, ast->codec->sample_rate); 00142 len -= 4; 00143 } else if (tag == TAG_VIDEOFRAME) { 00144 int ch_id = avio_rl16(pb); 00145 len -= 2; 00146 for(i=0; i<s->nb_streams; i++) { 00147 st = s->streams[i]; 00148 if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && st->id == ch_id) { 00149 frame = avio_rl16(pb); 00150 if ((res = av_get_packet(pb, pkt, len-2)) < 0) 00151 return res; 00152 pkt->pos = pos; 00153 pkt->pts = frame; 00154 pkt->stream_index = st->index; 00155 return pkt->size; 00156 } 00157 } 00158 } else if (tag == TAG_STREAMBLOCK) { 00159 for (i = 0; i < s->nb_streams; i++) { 00160 st = s->streams[i]; 00161 if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO && st->id == -1) { 00162 if (st->codec->codec_id == CODEC_ID_MP3) { 00163 avio_skip(pb, 4); 00164 if ((res = av_get_packet(pb, pkt, len-4)) < 0) 00165 return res; 00166 } else { // ADPCM, PCM 00167 if ((res = av_get_packet(pb, pkt, len)) < 0) 00168 return res; 00169 } 00170 pkt->pos = pos; 00171 pkt->stream_index = st->index; 00172 return pkt->size; 00173 } 00174 } 00175 } else if (tag == TAG_JPEG2) { 00176 for (i=0; i<s->nb_streams; i++) { 00177 st = s->streams[i]; 00178 if (st->codec->codec_id == CODEC_ID_MJPEG && st->id == -2) 00179 break; 00180 } 00181 if (i == s->nb_streams) { 00182 vst = av_new_stream(s, -2); /* -2 to avoid clash with video stream and audio stream */ 00183 if (!vst) 00184 return -1; 00185 vst->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00186 vst->codec->codec_id = CODEC_ID_MJPEG; 00187 av_set_pts_info(vst, 64, 256, swf->frame_rate); 00188 vst->codec->time_base = (AVRational){ 256, swf->frame_rate }; 00189 st = vst; 00190 } 00191 avio_rl16(pb); /* BITMAP_ID */ 00192 if ((res = av_new_packet(pkt, len-2)) < 0) 00193 return res; 00194 avio_read(pb, pkt->data, 4); 00195 if (AV_RB32(pkt->data) == 0xffd8ffd9 || 00196 AV_RB32(pkt->data) == 0xffd9ffd8) { 00197 /* old SWF files containing SOI/EOI as data start */ 00198 /* files created by swink have reversed tag */ 00199 pkt->size -= 4; 00200 avio_read(pb, pkt->data, pkt->size); 00201 } else { 00202 avio_read(pb, pkt->data + 4, pkt->size - 4); 00203 } 00204 pkt->pos = pos; 00205 pkt->stream_index = st->index; 00206 return pkt->size; 00207 } 00208 skip: 00209 avio_skip(pb, len); 00210 } 00211 return 0; 00212 } 00213 00214 AVInputFormat ff_swf_demuxer = { 00215 "swf", 00216 NULL_IF_CONFIG_SMALL("Flash format"), 00217 sizeof(SWFContext), 00218 swf_probe, 00219 swf_read_header, 00220 swf_read_packet, 00221 };