How well does Youtube preserve video/audio quality over the years?

[bitrape]

I remember back when most standard quality clips on Youtube were in FLV container with h.263/MP3 streams. Then at some point Youtube switched to MP4 h.264/AAC. Presumably they re-converted all those old clips to this format meaning the quality was degraded. Does have any info to shed some light on this?

Also, as I side note, WEBM VP9/Opus is really taking off now so I guess they are converting those clips AGAIN to this new format??

[poisondeathray]

I remember back when most standard quality clips on Youtube were in FLV container with h.263/MP3 streams. Then at some point Youtube switched to MP4 h.264/AAC. Presumably they re-converted all those old clips to this format meaning the quality was degraded. Does have any info to shed some light on this?

Also, as I side note, WEBM VP9/Opus is really taking off now so I guess they are converting those clips AGAIN to this new format??

The original files are stored on YT server.

The original files are re-converted

[bitrape]

I remember back when most standard quality clips on Youtube were in FLV container with h.263/MP3 streams. Then at some point Youtube switched to MP4 h.264/AAC. Presumably they re-converted all those old clips to this format meaning the quality was degraded. Does have any info to shed some light on this?

Also, as I side note, WEBM VP9/Opus is really taking off now so I guess they are converting those clips AGAIN to this new format??

The original files are stored on YT server.

The original files are re-converted

So every time a they convert to a new format or resolution they always use the originals?

[Cornucopia]

Yes that's how all the more professional sites would do it.

Scott