how to improve video quality

Transloadit
1

Archived from the Transloadit support forum. Originally posted on November 11, 2011; details may be outdated, see our docs for current behavior. Original thread

We’re seeing a lot of video fragmentation in our converted videos. do you know of any way we could increase the quality of our flv converted videos to keep this from happening?

Best,

Chris

2

Hello???

3

Hi Chris,

please provide an assembly id.

General you can improve your video quality when you specify the vpre parameter and set realtime to false:

"realtime": false,
"vpre": [
    "slow"
  ]

Kind regards,
Karl Skomski

4

Additionally, you could use for example use the sameq parameter to preserve the quality of the original video.

5

Will the “sameq” param work with realtime?

6

This is the template I am using. Could you show me how to set it up to still have realtime but to improve the video quality? Also right now the sound seems to slowly get more and more out of sync.

This is pretty urgent as we have beta user complaining and refusing to upload more video until it is fixed.

{ "steps": {
    "realtime_flash_video": {
      "use": ":original",
      "robot": "/video/encode",
      "preset": "flash",
      "width": 590,
      "height": 332,
      "realtime": true
    },
    "extracted_thumbs": {
      "use": ":original",
      "robot": "/video/thumbs",
      "width": 200,
      "height": 113,
      "count": 1,
      "format": "png"
    },
    "export": {
      "use":["realtime_flash_video","extracted_thumbs"],
      "robot": "/s3/store",
      "key": ********,
      "secret": ********,
      "bucket": "eevideos"
    }
} }
7

If sameq is too much, you can also set custom bitrates.
If you provide an assembly_id or the original input files we could do some testing

8

how do I set sameq or custom bitrates though? I don’t see them in the documentation.

9

??

10

Hi Chris,

Custom bitrate (800k):

"realtime_flash_video": {
  "use": ":original",
  "robot": "/video/encode",
  "preset": "flash",
  "width": 590,
  "height": 332,
  "realtime": true,
  "ffmpeg": { "b": "800K" }
}

Same quality:

"realtime_flash_video": {
  "use": ":original",
  "robot": "/video/encode",
  "preset": "flash",
  "width": 590,
  "height": 332,
  "realtime": true,
  "ffmpeg": {
    "sameq": true
  }
}

Kind regards,
Karl Skomski

11

Thanks you guys! This is a huge improvement.

I’ll mess around with the settings between using sameq and the bit rate and see if I can find a happy medium of quality and processing time.

Thanks a lot!