libavformat/swfdec.c

   1 /*
   2  * Flash Compatible Streaming Format demuxer
   3  * Copyright (c) 2000 Fabrice Bellard
   4  * Copyright (c) 2003 Tinic Uro
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "libavutil/intreadwrite.h"
  24 #include "swf.h"
  25
  26 static int get_swf_tag(ByteIOContext *pb, int *len_ptr)
  27 {
  28     int tag, len;
  29
  30     if (url_feof(pb))
  31         return -1;
  32
  33     tag = get_le16(pb);
  34     len = tag & 0x3f;
  35     tag = tag >> 6;
  36     if (len == 0x3f) {
  37         len = get_le32(pb);
  38     }
  39 //    av_log(NULL, AV_LOG_DEBUG, "Tag: %d - Len: %d\n", tag, len);
  40     *len_ptr = len;
  41     return tag;
  42 }
  43
  44
  45 static int swf_probe(AVProbeData *p)
  46 {
  47     /* check file header */
  48     if ((p->buf[0] == 'F' || p->buf[0] == 'C') && p->buf[1] == 'W' &&
  49         p->buf[2] == 'S')
  50         return AVPROBE_SCORE_MAX;
  51     else
  52         return 0;
  53 }
  54
  55 static int swf_read_header(AVFormatContext *s, AVFormatParameters *ap)
  56 {
  57     SWFContext *swf = s->priv_data;
  58     ByteIOContext *pb = s->pb;
  59     int nbits, len, tag;
  60
  61     tag = get_be32(pb) & 0xffffff00;
  62
  63     if (tag == MKBETAG('C', 'W', 'S', 0)) {
  64         av_log(s, AV_LOG_ERROR, "Compressed SWF format not supported\n");
  65         return AVERROR(EIO);
  66     }
  67     if (tag != MKBETAG('F', 'W', 'S', 0))
  68         return AVERROR(EIO);
  69     get_le32(pb);
  70     /* skip rectangle size */
  71     nbits = get_byte(pb) >> 3;
  72     len = (4 * nbits - 3 + 7) / 8;
  73     url_fskip(pb, len);
  74     swf->frame_rate = get_le16(pb); /* 8.8 fixed */
  75     get_le16(pb); /* frame count */
  76
  77     swf->samples_per_frame = 0;
  78     s->ctx_flags |= AVFMTCTX_NOHEADER;
  79     return 0;
  80 }
  81
  82 static int swf_read_packet(AVFormatContext *s, AVPacket *pkt)
  83 {
  84     SWFContext *swf = s->priv_data;
  85     ByteIOContext *pb = s->pb;
  86     AVStream *vst = NULL, *ast = NULL, *st = 0;
  87     int tag, len, i, frame, v;
  88
  89     for(;;) {
  90         tag = get_swf_tag(pb, &len);
  91         if (tag < 0)
  92             return AVERROR(EIO);
  93         if (tag == TAG_VIDEOSTREAM && !vst) {
  94             int ch_id = get_le16(pb);
  95             get_le16(pb);
  96             get_le16(pb);
  97             get_le16(pb);
  98             get_byte(pb);
  99             /* Check for FLV1 */
 100             vst = av_new_stream(s, ch_id);
 101             if (!vst)
 102                 return -1;
 103             vst->codec->codec_type = CODEC_TYPE_VIDEO;
 104             vst->codec->codec_id = codec_get_id(swf_codec_tags, get_byte(pb));
 105             av_set_pts_info(vst, 64, 256, swf->frame_rate);
 106             vst->codec->time_base = (AVRational){ 256, swf->frame_rate };
 107             len -= 10;
 108         } else if ((tag == TAG_STREAMHEAD || tag == TAG_STREAMHEAD2) && !ast) {
 109             /* streaming found */
 110             int sample_rate_code;
 111             get_byte(pb);
 112             v = get_byte(pb);
 113             swf->samples_per_frame = get_le16(pb);
 114             ast = av_new_stream(s, -1); /* -1 to avoid clash with video stream ch_id */
 115             if (!ast)
 116                 return -1;
 117             swf->audio_stream_index = ast->index;
 118             ast->codec->channels = 1 + (v&1);
 119             ast->codec->codec_type = CODEC_TYPE_AUDIO;
 120             ast->codec->codec_id = codec_get_id(swf_audio_codec_tags, (v>>4) & 15);
 121             ast->need_parsing = AVSTREAM_PARSE_FULL;
 122             sample_rate_code= (v>>2) & 3;
 123             if (!sample_rate_code)
 124                 return AVERROR(EIO);
 125             ast->codec->sample_rate = 11025 << (sample_rate_code-1);
 126             av_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
 127             len -= 4;
 128         } else if (tag == TAG_VIDEOFRAME) {
 129             int ch_id = get_le16(pb);
 130             len -= 2;
 131             for(i=0; i<s->nb_streams; i++) {
 132                 st = s->streams[i];
 133                 if (st->codec->codec_type == CODEC_TYPE_VIDEO && st->id == ch_id) {
 134                     frame = get_le16(pb);
 135                     av_get_packet(pb, pkt, len-2);
 136                     pkt->pts = frame;
 137                     pkt->stream_index = st->index;
 138                     return pkt->size;
 139                 }
 140             }
 141         } else if (tag == TAG_STREAMBLOCK) {
 142             st = s->streams[swf->audio_stream_index];
 143             if (st->codec->codec_id == CODEC_ID_MP3) {
 144                 url_fskip(pb, 4);
 145                 av_get_packet(pb, pkt, len-4);
 146             } else { // ADPCM, PCM
 147                 av_get_packet(pb, pkt, len);
 148             }
 149             pkt->stream_index = st->index;
 150             return pkt->size;
 151         } else if (tag == TAG_JPEG2) {
 152             for (i=0; i<s->nb_streams; i++) {
 153                 st = s->streams[i];
 154                 if (st->id == -2)
 155                     break;
 156             }
 157             if (i == s->nb_streams) {
 158                 vst = av_new_stream(s, -2); /* -2 to avoid clash with video stream and audio stream */
 159                 if (!vst)
 160                     return -1;
 161                 vst->codec->codec_type = CODEC_TYPE_VIDEO;
 162                 vst->codec->codec_id = CODEC_ID_MJPEG;
 163                 av_set_pts_info(vst, 64, 256, swf->frame_rate);
 164                 vst->codec->time_base = (AVRational){ 256, swf->frame_rate };
 165                 st = vst;
 166             }
 167             get_le16(pb); /* BITMAP_ID */
 168             av_new_packet(pkt, len-2);
 169             get_buffer(pb, pkt->data, 4);
 170             if (AV_RB32(pkt->data) == 0xffd8ffd9 ||
 171                 AV_RB32(pkt->data) == 0xffd9ffd8) {
 172                 /* old SWF files containing SOI/EOI as data start */
 173                 /* files created by swink have reversed tag */
 174                 pkt->size -= 4;
 175                 get_buffer(pb, pkt->data, pkt->size);
 176             } else {
 177                 get_buffer(pb, pkt->data + 4, pkt->size - 4);
 178             }
 179             pkt->stream_index = st->index;
 180             return pkt->size;
 181         }
 182         url_fskip(pb, len);
 183     }
 184     return 0;
 185 }
 186
 187 AVInputFormat swf_demuxer = {
 188     "swf",
 189     NULL_IF_CONFIG_SMALL("Flash format"),
 190     sizeof(SWFContext),
 191     swf_probe,
 192     swf_read_header,
 193     swf_read_packet,
 194 };