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flyvholm · 2nd February 2015, 05:46

I have a stubborn H.264 playback problem. A friend and I have spent weeks troubleshooting without finding out what's wrong, so it's time to ask the experts for help.

I've produced a film that I'll be offering as digital download. On all devices I've tested things work as expected: Film looks fine, and higher bitrate gives better visual quality.

My friend is in the US, I'm in Denmark. He has been testing the same video files and is seeing the opposite: Higher bitrate gives heavy artifacts. In particular, the noise becomes so ugly that the film isn't presentable at all. This is consistent across a number of HDTVs (he went to a store to try a bunch), either playing back from a USB stick, portable media players or a laptop.

I've tried using Adobe Media Encoder + MainConcept w. various settings (incl. stock settings) and also VirtualDub + x264 + mp4box w. various settings. The above observations have applied regardless what I've tried. The only way we've been able to make the film look decent on HDTVs on his end is by using heavy compression (i.e. 2.5 mbps for 1080p). Apparently this reduces the problem to an acceptable level by simply smearing out the noise. But that certainly doesn't look better on my end, so it's not a solution I'm happy with.

It's quite perplexing that he cannot find any HDTV setup where the film doesn't look horrible at normal bitrates, while I've also tested various HDTV setups and not seen the problem anywhere, using the same video files. So I would very much like to know what results other people are getting. I've compiled two samples for testing, using x264:
High bitrate sample (8mbps)
Low bitrate sample (2.5mbps)

Test results or comments regarding this issue highly appreciated.

2nd February 2015, 05:46	#1 \| Link
flyvholm Semper Tiro Join Date: Jan 2015 Location: Denmark Posts: 29	H.264 playback nightmare I have a stubborn H.264 playback problem. A friend and I have spent weeks troubleshooting without finding out what's wrong, so it's time to ask the experts for help. I've produced a film that I'll be offering as digital download. On all devices I've tested things work as expected: Film looks fine, and higher bitrate gives better visual quality. My friend is in the US, I'm in Denmark. He has been testing the same video files and is seeing the opposite: Higher bitrate gives heavy artifacts. In particular, the noise becomes so ugly that the film isn't presentable at all. This is consistent across a number of HDTVs (he went to a store to try a bunch), either playing back from a USB stick, portable media players or a laptop. I've tried using Adobe Media Encoder + MainConcept w. various settings (incl. stock settings) and also VirtualDub + x264 + mp4box w. various settings. The above observations have applied regardless what I've tried. The only way we've been able to make the film look decent on HDTVs on his end is by using heavy compression (i.e. 2.5 mbps for 1080p). Apparently this reduces the problem to an acceptable level by simply smearing out the noise. But that certainly doesn't look better on my end, so it's not a solution I'm happy with. It's quite perplexing that he cannot find any HDTV setup where the film doesn't look horrible at normal bitrates, while I've also tested various HDTV setups and not seen the problem anywhere, using the same video files. So I would very much like to know what results other people are getting. I've compiled two samples for testing, using x264: High bitrate sample (8mbps) Low bitrate sample (2.5mbps) Test results or comments regarding this issue highly appreciated.