Some questions regarding h264/mp4/avi compression

[jrtly]

Hello and good day to all, long story short I've been playing around with few video editing programs for some time now, and the only thing I've always struggled with was rendering properly using the xvid codec and, now, the h264 codec.

I usually film something with my phone or DSLR, import the clips into Sony's Vegas, edit it and then output using h264 as an .AVI. My first problem with Vegas is that I apparently cannot export as an .mp4, but only as an .avi wrapper or container. This would be my first question, is there any way I could force Vegas to export my clip as mp4/h264 ?
Is there any quality/size difference between .avi and .mp4 ? - I use x264vfw, btw.

Secondly, I know my phone or DSLR doesn't shoot proper RAW/Uncompressed video files - there is some compression, is there any advantage in decompressing (converting it to uncompressed .AVI for example) the original clip, before editing and final rendering ? Or should I just use the original video file ? Should I decompress as .avi or using the original file's format ? And is there any program out there, preferably free, that could tell me the video file's format, as in wrapper and codec used, exact fps, etc ... or any other metadata for that matter ?

As I've mentioned before, I use x264vfw for compressing in h264 - is there any manual or proper in-depth tutorial for it ? I've seen many tutorials on Youtube, but most of them just tell you what to do, they don't explain what every setting is used for. I'd like to properly understand how this codec works, I don't just wanna copy and paste someone else's settings and hope for the best.

And what settings are best quality-wise for Youtube ? When I render h264 1080p, 25fps, with a target bitrate of 8000kbps, the video looks fine, good even on my PC but when uploaded to Youtube, it looses quality, it's like Youtube is rendering the video again. What settings should I use for best quality on Youtube for 1080p ?

The last thing on my mind is regarding my CPU. I have an FX 8350 CPU from AMD and running Windows 7 64bit, and was wondering if modern codecs are optimised for multi-core rendering, in other words does x264vfw or any other codec fully utilise all my cores when rendering ? Or do I need specific versions of a codec in order for this to work properly ?

Sorry for my english mistakes, it's not my native language and I do hope I'll get to find out my answers. Thank you all for your time and attention.

[poisondeathray]

My first problem with Vegas is that I apparently cannot export as an .mp4, but only as an .avi wrapper or container. This would be my first question, is there any way I could force Vegas to export my clip as mp4/h264 ?
Is there any quality/size difference between .avi and .mp4 ? - I use x264vfw, btw.

You can if you use Sony AVC or Mainconcept AVC

x264vfw cannot, unless you use the commandline box - but there will be no audio

Alternatively , you can just remux it later , or use something like debugmode frameserver to a x264 CLI GUI

Secondly, I know my phone or DSLR doesn't shoot proper RAW/Uncompressed video files - there is some compression, is there any advantage in decompressing (converting it to uncompressed .AVI for example) the original clip, before editing and final rendering ? Or should I just use the original video file ? Should I decompress as .avi or using the original file's format ? And is there any program out there, preferably free, that could tell me the video file's format, as in wrapper and codec used, exact fps, etc ... or any other metadata for that matter ?

mediainfoxp to look at some of the characteristics

No advantage to decompression or converting in terms of quality. Unless you mean in terms of editing performance (maybe an editing codec like cineform) for timeline scrubbing performance

In fact, uncompressed will usually produce poor performance because of I/O transfer rate limitations from high bitrates, unless you have a Raid-0 array or SSD for the files

As I've mentioned before, I use x264vfw for compressing in h264 - is there any manual or proper in-depth tutorial for it ? I've seen many tutorials on Youtube, but most of them just tell you what to do, they don't explain what every setting is used for. I'd like to properly understand how this codec works, I don't just wanna copy and paste someone else's settings and hope for the best.

No there isn't. There is a lot to learn - even with an explantion of all the settings, you have to be able to apply them to different scenarios in different combinations.

You can look at the old reference for a short description of the settings (it's down, but look at the wayback machine which has it archived)
http://mewiki.project357.com/wiki/X264_Settings

And what settings are best quality-wise for Youtube ? When I render h264 1080p, 25fps, with a target bitrate of 8000kbps, the video looks fine, good even on my PC but when uploaded to Youtube, it looses quality, it's like Youtube is rendering the video again. What settings should I use for best quality on Youtube for 1080p ?

It really doesn't matter much in the end. Just upload something decent looking. YT is the lowest common denominator. It always re-encodes and destroys the quality. There is no passthrough on youtube. Even if you upload a near lossless version maybe 10x the filesize, it will still look the same so it's not worth it. In fact, higher quality version may look worse, because YT struggles to retain all the details at a low bitrate. A pre-filtered / denoised version might look slightly better on YT

The last thing on my mind is regarding my CPU. I have an FX 8350 CPU from AMD and running Windows 7 64bit, and was wondering if modern codecs are optimised for multi-core rendering, in other words does x264vfw or any other codec fully utilise all my cores when rendering ? Or do I need specific versions of a codec in order for this to work properly ?

VFW is slower than CLI (but you can't use it directly with vegas), and vegas can also be a the bottleneck.

[jrtly]

poisondeathray - Thanks for your answers. I did find this : http://www.avidemux.org/admWiki/doku.php?id=tutorial:h.264 . It's a tutorial on h264 compression. Guess I'll check out Avidemux a bit. And mediainfoxp also.

Thanks.