Need help with export settings, mostly low bitrates

Ar_D · May 31, 2024, 2:30am

Keep in mind, this is generated with AI:-

libx264 vs H264_videotoolbox: libx264 is a software-based encoder and is generally more thorough in encoding, producing higher quality at the same bitrate compared to H264_videotoolbox, which is a hardware-based encoder. Stick with libx264 for better quality, especially given your low-quality source material.

Hardware vs Software Encoding: Software encoding (libx264) generally provides better image quality at the expense of longer encoding times. Given your goal for quality and given the poor quality of your footage, sticking with software encoding is probably better.

Interlaced vs Progressive: Interlaced video is largely a thing of the past and is mostly relevant for certain broadcast scenarios. Progressive scan mode is the better choice for online content, especially on forums and streaming platforms.

Deinterlacer Setting: Since your footage is progressive, the deinterlacer setting should have no effect. You can set it to the fastest option or ignore it altogether.

Lanczos Interpolation: Lanczos is a good choice for rescaling and should help with the pixelation issues you encounter when zooming in on low-quality footage. Stick with it.

Bitrate Control: Given your file size limit:
- Average Bitrate (ABR): This is a good approach if you have a specific file size in mind.
- Quality-Based (CRF): This could give you better quality for the same file size. A CRF value between 23 and 28 is typical for your use case, with lower values giving better quality but larger file sizes.
- Constrained VBR: This can provide a balance between ABR and CRF. It’s worth experimenting with.

Dual Pass Encoding: Dual pass can significantly improve the quality of your video at a given file size, especially for longer videos. It’s worth the extra time for your longer or more important videos.

GOP (Group of Pictures): A typical GOP size is around 60 (for 30fps video), which means a new keyframe every 2 seconds. Larger GOP sizes can reduce file size but might decrease quality in some scenarios.
B-Frames: These improve compression efficiency and can enhance quality without a significant file size increase. Default settings are usually fine.
Codec Threads: This setting controls multi-threading. More threads can speed up encoding but doesn’t directly affect quality. The default is usually adequate.

Resolution: Considering your source quality and zoom level, exporting at 720p seems reasonable. Dropping to 540p can further reduce file size but may worsen pixelation.
Bitrate: For a 15-minute video under 100 MB, you’d need an average bitrate of around 1 Mbps. For better quality, use VBR or CRF with dual pass encoding.
Profile and Tune: Use High profile and Tune: Film for better image quality.