Need help with encoding, video is blotchy where there are color gradients!

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Ethwyn

New member
My footages were shot using a Canon 7D at 1080p.

I'm using FCP, and I exported my final video using Apple ProRes. Then I used Compressor to compress the file to H264 mov format. However, the end product appears very blotchy throughout the whole video. I've used various media players to test and all yield the same result.

I've searched online for solutions to my problem, and all of them seem to say that it is a compression problem, where the videos used too big a compression. But I see that my overall bit rate is 27.3Mbps, which doesn't seem to be heavily compressed. Or am I wrong about this concept?

Can anyone help me with this problem? Thanks so much!

*I'ved used Final Cut Pro to do color correction to my footages, does this result in the blotchiness during export?

The following is a copy of what MediaInfo says:
Format : MPEG-4
Format profile : QuickTime
Codec ID : qt
File size : 3.49 GiB
Duration : 18mn 19s
Overall bit rate : 27.3 Mbps
Encoded date : UTC 2011-04-16 01:11:20
Tagged date : UTC 2011-04-16 01:14:07
Writing library : Apple QuickTime

Video
ID : 2
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L5.0
Format settings, CABAC : No
Format settings, ReFrames : 2 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 18mn 19s
Duration_LastFrame : 5mn 3s
Bit rate mode : Variable
Bit rate : 25.7 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.517
Stream size : 3.29 GiB (94%)
Language : English
Encoded date : UTC 2011-04-16 01:09:10
Tagged date : UTC 2011-04-16 01:14:07
Color primaries : BT.709-5, BT.1361, IEC 61966-2-4, SMPTE RP177
Transfer characteristics : BT.709-5, BT.1361
Matrix coefficients : BT.709-5, BT.1361, IEC 61966-2-4 709, SMPTE RP177

Audio
ID : 1
Format : PCM
Format settings, Endianness : Little
Format settings, Sign : Signed
Codec ID : sowt
Duration : 18mn 19s
Bit rate mode : Constant
Bit rate : 1 536 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 201 MiB (6%)
Language : English
Encoded date : UTC 2011-04-16 01:09:10
Tagged date : UTC 2011-04-16 01:14:07
 
Last edited:
Though Apple has a notoriously bad H.264 encoder, blocking at 27Mbits *is* kind of suspicious. I suggest using an x264-based encoder.
 
So it's ok to use the Compressor program to do the compressing job? I wonder if it has x264-based encoding...
 
Ethwyn said:
So it's ok to use the Compressor program to do the compressing job? I wonder if it has x264-based encoding...
Click to expand...

Compressor is from Apple, it is not x264 based at all. I suggest looking into the x264 mac, Handbreak, or a few other programs that use x264.
 
Chances are when you go from your 4:2:2 material to 4:2:0 you'll get banding in your gradients. The only way to fix it is to add noise, or dither.

Seek a professional compressionist if you don't want to add noise to your footage.
 
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