[vdr] How does VDR handle AFD?
christian at visual-page.de
Thu Sep 15 17:57:23 CEST 2005
Klaus Schmidinger wrote:
> Reinhard Nissl wrote:
>> Christian Gmeiner wrote:
>>> i am currently interested in this topic and wanted to know how VDR
>>> does handle this. If you dont know what AFD is:
>>> I think that VDR needs a menuentry where the user must specify what
>>> kind of tv-set he owns (4:3 or 16:9).
>>> If we add this we could make use of the AFD header in VDR. Maybe i
>>> am wrong and AFD is allready supported by VDR.
>> Well, I've added extracting AFD information in xine. But so far, I do
>> nothing more than storing this information as stream info.
>> As far as I can tell, VDR doesn't extract any AFD information from
>> video streams. But it should not be too complicated to add this to
>> cRemux::ScanVideoPacket(), due to the repacking of cVideoRepacker.
>> AFD information appears in the video stream after user data
>> startcodes (0x000001B2) and these appear before picture start codes
>> (0x00000100). Typically, there are only a few bytes between those
>> startcodes. And as cVideoRepacker ensures a new PES packet for each
>> picture, AFD information should be in the same 2048 byte block where
>> ScanVideoPacket() finds the picture start code.
>> The next few lines are from xine-lib/src/libmpeg2/decode.c:
>> /* check Active Format Description ETSI TS 101 154 V1.5.1 */
>> else if (buffer == 0x44 && buffer == 0x54 && buffer == 0x47
>> && buffer == 0x31)
>> int afd = (buffer & 0x40) ? (buffer & 0x0f) : -1;
>> _x_stream_info_set(mpeg2dec->stream, XINE_STREAM_INFO_VIDEO_AFD, afd);
>> And these are from xine-lib/include/xine.h:
>> /* possible values for XINE_STREAM_INFO_VIDEO_AFD */
>> #define XINE_VIDEO_AFD_NOT_PRESENT -1
>> #define XINE_VIDEO_AFD_RESERVED_0 0
>> #define XINE_VIDEO_AFD_RESERVED_1 1
>> #define XINE_VIDEO_AFD_BOX_16_9_TOP 2
>> #define XINE_VIDEO_AFD_BOX_14_9_TOP 3
>> #define XINE_VIDEO_AFD_BOX_GT_16_9_CENTRE 4
>> #define XINE_VIDEO_AFD_RESERVED_5 5
>> #define XINE_VIDEO_AFD_RESERVED_6 6
>> #define XINE_VIDEO_AFD_RESERVED_7 7
>> #define XINE_VIDEO_AFD_SAME_AS_FRAME 8
>> #define XINE_VIDEO_AFD_4_3_CENTRE 9
>> #define XINE_VIDEO_AFD_16_9_CENTRE 10
>> #define XINE_VIDEO_AFD_14_9_CENTRE 11
>> #define XINE_VIDEO_AFD_RESERVED_12 12
>> #define XINE_VIDEO_AFD_4_3_PROTECT_14_9 13
>> #define XINE_VIDEO_AFD_16_9_PROTECT_14_9 14
>> #define XINE_VIDEO_AFD_16_9_PROTECT_4_3 15
>> But don't expect this feature to be part of VDR-1.4.
> I wouldn't expect it to be part of _any_ VDR version.
> This is something the actual _player_device_ would have to do.
> Since VDR doesn't parse the video data in live mode, this would only
> work for recordings or Transfer Mode. cRemux with all this new cRepacker
> stuff is overloaded to the max as it is already...
Ok.. so will add afd stuff to dxr3 driver & plugin.
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> vdr at linuxtv.org
Developer for Rockbox (http://www.rockbox.org)
Maintainer of the DXR3-Plugin for VDR: http://sourceforge.net/projects/dxr3plugin/
Maintainer of VDR-Ebuilds at Gentoo.de
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