H.264 encoding advice for uncompressed VHS captures Blackmagic

[Ferggue]

Hello,

I’m looking for recommendations specifically about compression / encoding, starting from an uncompressed capture.
I am not looking to change capture hardware or capture format — only to improve the compression stage.


Source (capture master)

I capture VHS tapes using Blackmagic Intensity Pro with Media Express.
This is the file Media Express delivers:

Uncompressed master (.mov):

• Container: QuickTime (.mov)
  
• Video codec: 2vuy (UYVY)
  
• Resolution: 720×486 (clean aperture 704×480)
  
• Frame rate: 29.97 fps
  
• Scan type: Interlaced
  
• Field order: Bottom Field First
  
• Chroma: 4:2:2
  
• Bitrate: ~168 Mb/s
  
• Compression: Uncompressed / lossless
  
• Color matrix: BT.601 NTSC
  
• Audio: PCM 24-bit / 48 kHz

I’m satisfied with this file and keep it as the archival master.



Current compression (delivery file)

From this MOV, I encode using Adobe Media Encoder to H.264 MP4 for client delivery.


H.264 MP4 (current settings):

• Codec: H.264 (High@L3.1)
  
• Resolution: 720×484
  
• Frame rate: 29.97 fps
  
• Scan type: Interlaced
  
• Field order: Bottom Field First
  
• Chroma: 4:2:0
  
• Bitrate: ~2.1 Mb/s (VBR)
  
• Color matrix: BT.601
  
• Audio: AAC 192 kb/s

The problem

I understand the limitations of VHS and that H.264 is lossy, but the resulting MP4 looks noticeably softer than expected.
Fine detail seems to be lost, and the image feels over-smoothed / blurred, more than I would expect purely from the format change.

The uncompressed MOV clearly retains more usable detail than what survives the encode.


What I’m trying to achieve

• Deliver H.264 MP4 files (universally playable)
  
• Reasonable file size for home users
  
• Maximum perceived detail preserved from the master
  
• Content is home video, final use is home viewing

I am aware that deinterlacing happens during the H.264 encoding stage, and my question is not whether to deinterlace, but how to do this compression in the least destructive way.



My questions

1. Starting from this uncompressed 4:2:2 interlaced master, what would you recommend changing in the compression stage?
   
2. Is ~2 Mb/s too low for VHS in H.264 if detail preservation is the priority?
   
3. Would increasing bitrate alone help, or are there specific H.264 / x264-style settings (even conceptually, if not Adobe-specific) that better suit analog sources?
   
4. Are there common Adobe Media Encoder pitfalls when compressing analog interlaced material that I should avoid?

Thanks in advance.

[ozymango]

Hello,

I’m looking for recommendations specifically about compression / encoding, starting from an uncompressed capture.

From this MOV, I encode using Adobe Media Encoder to H.264 MP4 for client delivery.


H.264 MP4 (current settings):
[LIST][*]Codec: H.264 (High@L3.1)
[*]Resolution: 720×484
[*]Frame rate: 29.97 fps
[*]Scan type: Interlaced

I am aware that deinterlacing happens during the H.264 encoding stage, and my question is not whether to deinterlace, but how to do this compression in the least destructive way.

Hello. It sounds like you're transfering/creating videos for customers/clients? Well even if this is just for home use, while I'm not up on the latest versions of Adobe Media Encoder, I'm not all all clear on your interlaced/deinterlaced final output with your x264 files, and that could be a big issue right there, in terms of image quality.

Short version: I can see no reason why you want to have interlaced x264 files, and from my own experience, for best results, you want to deinterlace your video *before* you convert it to x264. That is, don't trust your media encoder to compress the video *and* deinterlace at the same time -- deinterlace first, and make sure that looks good, before then outputting to any compressed format.

I'm not at all clear on your workflow, but if you're currently doing the compression and deinterlacing at the same time, I'd change the steps so:

1) Capture uncompressed video
2) Deinterlace uncompressed video using AviSynth and QTGMC -- tons and tons of posts and articles and commentary on doing this step
3) Then compress your now-progressive video.

The deinterlacing step using AviSynth and QTGMC has really helped improve the quality of my own VHS captures, *IF* the intent is not to make into standard DVDs, but to share as x264 files.

[davexnet]

Perhaps a small sample of the source and corresponding h.264 encode wourld be useful

[Alwyn]

2000kbps is too low IMO. I use at least 5000kbps.