[Libav-user] Writing Interlaced Video

Nils Jessen jessen at irt.de
Thu Jun 12 11:17:12 CEST 2014


Thank you Carl!

I will try to explain it a little bit better (my knowledge is quite 
limited though).

V210 should be able to store interlaced footage (per line, in one 
"frame" see [2]). All odd lines in the "frame" representing one 
interlaced frame and all the even another. The source footage is already 
in this format, so I basicly need to tell the decoder the footage is 
indeed interlaced and which "field" comes first.

Using all the interlaced options mentioned the output looks exactly the 
same as the progressive source from the header perspective. Watching the 
avi in vlc looks heavily interlaced, meaning both interlaced frame are 
shown at the same time and the frame rate is not doubled (or progressive 
in other words). If I turn the "anti-interlacing" on, the artifacts 
disappear.

So how can I add the header information?
Since the avi container can not store this information, I think the flag 
needs to be embedded in the codec header inside the avi... right?

[1] 
https://developer.apple.com/library/mac/technotes/tn2162/_index.html#//apple_ref/doc/uid/DTS40013070-CH1-TNTAG8-V210__4_2_2_COMPRESSION_TYPE
[2] http://www.digitalpreservation.gov/formats/fdd/fdd000353.shtml
[3] 
http://ffmpeg-users.933282.n4.nabble.com/Forcing-interlaced-handling-td4347858.html

Am 11.06.2014 22:06, schrieb Carl Eugen Hoyos:
> Nils Jessen <jessen at ...> writes:
>
>> Everything works perfectly fine using AV_CODEC_ID_V210
>> and AV_PIX_FMT_YUV422P10LE writing progressive material,
>> but I am not able to set the output format to interlaced.
> Are you sure that v210 supports interlacing?
>
> Or in other words: Are you worried because
> your frames *look* progressive or because
> you want to signal to your decoder that
> they are interlaced?
>
> In case this is your question: I don't think you can
> store fields in v210 (the way it is possible in
> h264 and mpeg2 video).
>
> Carl Eugen
>
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