Read references in swf files

[TopsLuo]

Summary of the bug:
I am trying to transcode swf to mpegts format,But I failed.
Use the tool to analysis SWF file:

<?xml version="1.0" encoding="utf-8"?>
<SWF type="CWS" Version="9" FileLength="257819" width="640" height="480" FrameRate="18" FrameCount="270">
  <tags count="302">
    <FileAttributes class="zero.swf.tagBodys.FileAttributes" UseGPU="false" UseDirectBlit="false" HasMetadata="false" ActionScript3="false" suppressCrossDomainCaching="false" swfRelativeUrls="false" UseNetwork="true" rest="0x00000000"/>
    <block swfSrc="aa.swf" offset="27" length="257792"/>
  </tags>
</SWF>

,It says the file have 270 frames,buf FFmpeg only decoded one Frame

$ ./bin/ffmpeg.exe -i ../aa.swf test.ts
ffmpeg version N-81635-gbc7066f Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.4.0 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-libebur128 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib
  libavutil      55. 29.100 / 55. 29.100
  libavcodec     57. 55.101 / 57. 55.101
  libavformat    57. 48.103 / 57. 48.103
  libavdevice    57.  0.102 / 57.  0.102
  libavfilter     6. 61.100 /  6. 61.100
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  1.100 /  2.  1.100
  libpostproc    54.  0.100 / 54.  0.100
[swf @ 0000000000726de0] SWF compressed file detected
[swf @ 0000000000726de0] Could not find codec parameters for stream 1 (Video: none, none): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[swf @ 0000000000726de0] Could not find codec parameters for stream 2 (Video: vp6f, none): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, swf, from '../aa.swf':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: mjpeg, yuvj444p(pc, bt470bg/unknown/unknown), 640x480, 18 tbr, 18 tbn
    Stream #0:1: Video: none, none, 18 tbr, 18 tbn
    Stream #0:2: Video: vp6f, none, 18 tbr, 18 tbn
[swscaler @ 000000000294ae20] deprecated pixel format used, make sure you did set range correctly
[mpegts @ 00000000028f7de0] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
Output #0, mpegts, to 'test.ts':
  Metadata:
    encoder         : Lavf57.48.103
    Stream #0:0: Video: mpeg2video (Main), yuv420p, 640x480, q=2-31, 200 kb/s, 18 fps, 90k tbn, 18 tbc
    Metadata:
      encoder         : Lavc57.55.101 mpeg2video
    Side data:
      cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg (native) -> mpeg2video (native))
Press [q] to stop, [?] for help
frame=    1 fps=0.0 q=5.3 Lsize=      35kB time=00:00:00.00 bitrate=25841454.5kbits/s speed=0.000491x
video:32kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 9.057426%

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

[Carl Eugen Hoyos]

Does your "tool" allow to transcode the file you provided? Please upload the expected output.

The (uncompressed) file you provided is 257819 bytes. the (second) jpg ends at position 216518. It is very unlikely that 40k provide 270 frames.

[Carl Eugen Hoyos]

Or are you searching for this file?
​http://pop.img.ledu.com/5232/flv.f4v

[TopsLuo]

Tool name is "SWFtoVideoProPortable 3.12.00",it does transcode sucessful.But where should I upload the output file?

[TopsLuo]

Tool name is "SWFtoVideoProPortable 3.12.00",it does transcode sucessful.But where should I upload the output file?

[TopsLuo]

the output file

[Carl Eugen Hoyos]

Not sure how likely this is to get implemented.
Does the original file conform to a known specification?

[TopsLuo]

Replying to cehoyos:

Not sure how likely this is to get implemented.
Does the original file conform to a known specification?

I think YES.Otherwise the tool can't transcoding.

[Carl Eugen Hoyos]

Iiuc, the relevant tag is starting at 0x32f88, a DefineSprite tag (39) with length 886 that contains an DoAction tag (12) with length 842. The first action is an ActionConstantPool (0x88) that defines 30 strings (including the relevant parts of the url ​http://pop.img.ledu.com/5232/flv.f4v), followed by an ActionDefineFunction (0x9b) with the name "video_replay" and several ActionPush actions.

[TopsLuo]

Thank you very much.You mean a SWF file has no real video content, but through the URL to specify the video file?

[Carl Eugen Hoyos]

I don't disagree strongly but there are quite a few tickets open that are less likely to get implemented.