[FFmpeg-devel] regression - mpeg2 interlace/topfield flags not set anymore

christophelorenz christophelorenz
Thu Jan 24 15:46:50 CET 2008


Seems something has changed between rev 10908 and current causing the 
interlaced and field order flag to be set to a wrong value.

ffmpeg -i "source.avi" -y -flags +ildct+ilme -bufsize 2000k -b 7600k 
-maxrate 8000k -top 1 -vcodec mpeg2video output.m2v

Bitrate viewer output with ffmpeg rev 10908 :

Num. of picture read: 998
Stream type: MPEG-2  MP at ML  VBR
Resolution: 720*576
Aspect ratio: 1:1 VGA      
Framerate: 25.00
Nom. bitrate: 8000000 Bit/Sec
VBV buffer size: 123
Constrained param. flag: No
Chroma format: 4:2:0
DCT precision: 8
Pic. structure: Frame
Field topfirst: Yes
DCT type: Field
Quantscale: Linear
Scan type: ZigZag
Frame type: Interlaced

Same command with rev 11213 :
(note frame number, Field topfirst and frame type that are wrong)

Num. of picture read: 499
Stream type: MPEG-2  MP at ML  VBR
Resolution: 720*576
Aspect ratio: 1:1 VGA      
Framerate: 25.00
Nom. bitrate: 8000000 Bit/Sec
VBV buffer size: 123
Constrained param. flag: No
Chroma format: 4:2:0
DCT precision: 8
Pic. structure: Frame
Field topfirst: No
DCT type: Frame
Quantscale: Linear
Scan type: ZigZag
Frame type: Progressive

Changing to -top 0 doesn't work either.
Tried source avi in DV and raw YUV.

Chris.





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