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 "swf.h"
  24
  25 static int get_swf_tag(ByteIOContext *pb, int *len_ptr)
  26 {
  27     int tag, len;
  28
  29     if (url_feof(pb))
  30         return -1;
  31
  32     tag = get_le16(pb);
  33     len = tag & 0x3f;
  34     tag = tag >> 6;
  35     if (len == 0x3f) {
  36         len = get_le32(pb);
  37     }
  38 //    av_log(NULL, AV_LOG_DEBUG, "Tag: %d - Len: %d\n", tag, len);
  39     *len_ptr = len;
  40     return tag;
  41 }
  42
  43
  44 static int swf_probe(AVProbeData *p)
  45 {
  46     /* check file header */
  47     if ((p->buf[0] == 'F' || p->buf[0] == 'C') && p->buf[1] == 'W' &&
  48         p->buf[2] == 'S')
  49         return AVPROBE_SCORE_MAX;
  50     else
  51         return 0;
  52 }
  53
  54 static int swf_read_header(AVFormatContext *s, AVFormatParameters *ap)
  55 {
  56     SWFContext *swf = s->priv_data;
  57     ByteIOContext *pb = s->pb;
  58     int nbits, len, tag;
  59
  60     tag = get_be32(pb) & 0xffffff00;
  61
  62     if (tag == MKBETAG('C', 'W', 'S', 0)) {
  63         av_log(s, AV_LOG_ERROR, "Compressed SWF format not supported\n");
  64         return AVERROR(EIO);
  65     }
  66     if (tag != MKBETAG('F', 'W', 'S', 0))
  67         return AVERROR(EIO);
  68     get_le32(pb);
  69     /* skip rectangle size */
  70     nbits = get_byte(pb) >> 3;
  71     len = (4 * nbits - 3 + 7) / 8;
  72     url_fskip(pb, len);
  73     swf->frame_rate = get_le16(pb); /* 8.8 fixed */
  74     get_le16(pb); /* frame count */
  75
  76     swf->samples_per_frame = 0;
  77     s->ctx_flags |= AVFMTCTX_NOHEADER;
  78     return 0;
  79 }
  80
  81 static int swf_read_packet(AVFormatContext *s, AVPacket *pkt)
  82 {
  83     SWFContext *swf = s->priv_data;
  84     ByteIOContext *pb = s->pb;
  85     AVStream *vst = NULL, *ast = NULL, *st = 0;
  86     int tag, len, i, frame, v;
  87
  88     for(;;) {
  89         tag = get_swf_tag(pb, &len);
  90         if (tag < 0)
  91             return AVERROR(EIO);
  92         if (tag == TAG_VIDEOSTREAM && !vst) {
  93             int ch_id = get_le16(pb);
  94             get_le16(pb);
  95             get_le16(pb);
  96             get_le16(pb);
  97             get_byte(pb);
  98             /* Check for FLV1 */
  99             vst = av_new_stream(s, ch_id);
 100             if (!vst)
 101                 return -1;
 102             vst->codec->codec_type = CODEC_TYPE_VIDEO;
 103             vst->codec->codec_id = codec_get_id(swf_codec_tags, get_byte(pb));
 104             av_set_pts_info(vst, 64, 256, swf->frame_rate);
 105             vst->codec->time_base = (AVRational){ 256, swf->frame_rate };
 106             len -= 10;
 107         } else if ((tag == TAG_STREAMHEAD || tag == TAG_STREAMHEAD2) && !ast) {
 108             /* streaming found */
 109             int sample_rate_code;
 110             get_byte(pb);
 111             v = get_byte(pb);
 112             swf->samples_per_frame = get_le16(pb);
 113             ast = av_new_stream(s, -1); /* -1 to avoid clash with video stream ch_id */
 114             if (!ast)
 115                 return -1;
 116             swf->audio_stream_index = ast->index;
 117             ast->codec->channels = 1 + (v&1);
 118             ast->codec->codec_type = CODEC_TYPE_AUDIO;
 119             ast->codec->codec_id = codec_get_id(swf_audio_codec_tags, (v>>4) & 15);
 120             ast->need_parsing = AVSTREAM_PARSE_FULL;
 121             sample_rate_code= (v>>2) & 3;
 122             if (!sample_rate_code)
 123                 return AVERROR(EIO);
 124             ast->codec->sample_rate = 11025 << (sample_rate_code-1);
 125             av_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
 126             len -= 4;
 127         } else if (tag == TAG_VIDEOFRAME) {
 128             int ch_id = get_le16(pb);
 129             len -= 2;
 130             for(i=0; i<s->nb_streams; i++) {
 131                 st = s->streams[i];
 132                 if (st->codec->codec_type == CODEC_TYPE_VIDEO && st->id == ch_id) {
 133                     frame = get_le16(pb);
 134                     av_get_packet(pb, pkt, len-2);
 135                     pkt->pts = frame;
 136                     pkt->stream_index = st->index;
 137                     return pkt->size;
 138                 }
 139             }
 140         } else if (tag == TAG_STREAMBLOCK) {
 141             st = s->streams[swf->audio_stream_index];
 142             if (st->codec->codec_id == CODEC_ID_MP3) {
 143                 url_fskip(pb, 4);
 144                 av_get_packet(pb, pkt, len-4);
 145             } else { // ADPCM, PCM
 146                 av_get_packet(pb, pkt, len);
 147             }
 148             pkt->stream_index = st->index;
 149             return pkt->size;
 150         } else if (tag == TAG_JPEG2) {
 151             for (i=0; i<s->nb_streams; i++) {
 152                 st = s->streams[i];
 153                 if (st->id == -2)
 154                     break;
 155             }
 156             if (i == s->nb_streams) {
 157                 vst = av_new_stream(s, -2); /* -2 to avoid clash with video stream and audio stream */
 158                 if (!vst)
 159                     return -1;
 160                 vst->codec->codec_type = CODEC_TYPE_VIDEO;
 161                 vst->codec->codec_id = CODEC_ID_MJPEG;
 162                 av_set_pts_info(vst, 64, 256, swf->frame_rate);
 163                 vst->codec->time_base = (AVRational){ 256, swf->frame_rate };
 164                 st = vst;
 165             }
 166             get_le16(pb); /* BITMAP_ID */
 167             av_new_packet(pkt, len-2);
 168             get_buffer(pb, pkt->data, 4);
 169             if (AV_RB32(pkt->data) == 0xffd8ffd9 ||
 170                 AV_RB32(pkt->data) == 0xffd9ffd8) {
 171                 /* old SWF files containing SOI/EOI as data start */
 172                 /* files created by swink have reversed tag */
 173                 pkt->size -= 4;
 174                 get_buffer(pb, pkt->data, pkt->size);
 175             } else {
 176                 get_buffer(pb, pkt->data + 4, pkt->size - 4);
 177             }
 178             pkt->stream_index = st->index;
 179             return pkt->size;
 180         }
 181         url_fskip(pb, len);
 182     }
 183     return 0;
 184 }
 185
 186 AVInputFormat swf_demuxer = {
 187     "swf",
 188     NULL_IF_CONFIG_SMALL("Flash format"),
 189     sizeof(SWFContext),
 190     swf_probe,
 191     swf_read_header,
 192     swf_read_packet,
 193 };