7 This plugin is a demuxer for Microsoft's ASF Advanced Streaming Format
8 or ASF [1]. This demuxer only supports ASF v1.0 since the vast
9 majority of existing ASF files use that version. The specification
10 has been derived from a third party source [2] without reference to
16 The ASF format can carry any combination of audio, video or
17 'ASF_Command_Media' streams. For simplicity it is assumed that each
18 file can carry up to 16 audio streams and 16 video streams. These are
19 implemented as dynamic pads and appear as appropriate once the file
20 headers have been parsed.
22 (-------------------------)
32 (-------------------------)
35 Known stream fourccs are:
38 ------------------------------------------
39 H263 H263 I263 video/x-h263
41 MPEG4 DIVX divx DX50 video/mpeg
45 MSMPEG4V1 MPG4 video/mpeg
46 MSMPEG4V2 MP42 video/mpeg
47 MSMPEG4V3 MP43 DIV3 video/mpeg
48 WMV1 WMV1 video/x-wmv, wmvversion = (int) 1
49 WMV2 WMV2 video/x-wmv, wmvversion = (int) 2
50 WMV3 WMV3 video/x-wmv, wmvversion = (int) 3
51 WMA1 WMA1 audio/x-wma, wmaversion = (int) 1
52 WMA2 WMA2 audio/x-wma, wmaversion = (int) 2
53 audio/x-wma, wmaversion = (int) 3
55 These video stream headers is very similar to that used in the AVI
56 format as are the audio stream headers. In addition the content types
57 are basically the same also so, for compatibility with existing
58 plugins the src pads are set up as video/x-msvideo. This enables
59 compatibility with the ffmpeg plugin.
61 The demuxing process begins with the loop function gst_asf_demux_loop
62 and parses the file in a recursive tree as follows:
65 +-> gst_asf_demux_process_object() <----
66 +-> gst_asf_demux_process_stream() \
67 |-> gst_asf_demux_process_file() |
68 |-> gst_asf_demux_process_header() --+
69 |-> gst_asf_demux_process_data()
70 +-> gst_asf_demux_process_segment()
71 +-> gst_asf_demux_process_chunk()
76 - Support for ASF v2.0
77 - Support for command media streams
84 [1] Microsoft. ASF Specification - Windows Media Technologies.
85 http://www.microsoft.com/windows/windowsmedia/format/asfspec.aspx (v01.20.01e, September 2003)
87 [2] divx at euro.ru. ASF format version 1.0,
88 reconstruction. http://avifile.sourceforge.net/asf-1.0.htm