[Libav-user] Writing Interlaced Video

[Nils Jessen]

Hi!
I would like to get some help writing interlaced video correctly flagged 
as interlaced. Based on the muxing example I have implemented a method 
to write YUV422 10 Bit Avi using the V210 "codec". The input is also 
uncompressed (dpx files read into opencv::mat for manipulation) so I 
fill the AVFrame manually with data. 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.

So far I have played around with the following attributes:
c->field_order
picture->interlaced_frame
picture->top_field_first

Since I do not want to convert anything, all I need is the meta 
information specified in the V210 codec header (somewhere inside the avi 
chunk) afaik. Testing all the attributes mentioned above, the output.avi 
is still "progressive" all the time (both fields in the same frame). The 
interlaced data is stored inside a single frame / dpx file btw. So by 
defining the codecs field order (e.g AV_FIELD_TT) and the AVFrames 
interlace / field type I thought it could work.

If this is not yet implemented for this format, where could I start 
looking to add the meta information (the interlace flag) myself?

Thanks in advance for your help!