Video format conversion cheat sheet for streaming?

Discussion in 'DSLR Video Discussion' started by rocketcityman, Jan 28, 2018.

  1. rocketcityman

    rocketcityman TPF Noob!

    Joined:
    Jan 12, 2018
    Messages:
    12
    Likes Received:
    0
    Can others edit my Photos:
    Photos NOT OK to edit
    This is a bit broader than just a DSLR video question, though I do shoot video on a Panasonic Lumix G3 and edit it in Sony Vegas (video mostly imported as AVCHD), pertaining to good video conversion source-to-destination mappings when dealing with video in post/editing. I often deal with video in an MP4 container with AVC or H.264 codec format under the hood (I noticed one video someone sent me even had "MPEG 4 Visual" Advanced Simple@L3 as the name of the codec, which I hadn't seen before), but occasionally I have wmv files (which use the VC-1 codec) or quicktime (where I saw the MPEG4 Visual) as source videos.

    Amidst all the various transcoding options I'm confused about the best source-to-destination (like AVC to H.264) pairings for video that would be either uploaded to sites like Vimeo or YouTube (where I think they even apply their own additional transcoding) or for home video you might want to stream on a LAN media server. Occasionally my 2K+ videos will go to DVD/MPEG-2 as well. I know that some people say that certain formats are only ideal as final delivery/playback formats but not good for dragging into an editor as an editing format before you render it/transcode it to a different output format, because if you do you will lose quality editing in a less than ideal format.

    Has anyone with video editing experience developed any kind of cheatsheet (literally a spreadsheet comes to mind with source/destination format columns) for video conversions with any kind of "great|good| mediocre|bad" rating (based on video quality, bitrate, file size, and amount of lossy-ness) for codec transcoding - at least in the realm of home video or video intended for streaming? Even a few comments on certain formats would be helpful that I could compile into a sheet of my own.

    Thanks in advance!


     
    Last edited: Jan 28, 2018
  2. rocketcityman

    rocketcityman TPF Noob!

    Joined:
    Jan 12, 2018
    Messages:
    12
    Likes Received:
    0
    Can others edit my Photos:
    Photos NOT OK to edit
    This article for example suggests that editing in AVCHD (which I do 99% of the time!) is not ideal, so maybe I've been doing that wrong all along since I drag AVCHD video from my camera straight into Vegas and start editing immediately and convert it to mp4 at the end (looks like it keeps the codec as "AVC" though in mp4 format).


    But also knowing a good editing format to convert something already in MPEG2 format to (if taken from a DVD disk) would be good to know too. If you go from MPEG2 to some MP4 format then back to MPEG2 I assume you are going to lose some quality that was in the original MPEG2.
     
    Last edited: Jan 28, 2018
  3. CherylL

    CherylL TPF Supporters Supporting Member

    Joined:
    Aug 6, 2012
    Messages:
    956
    Likes Received:
    616
    Location:
    near St Louis
    Can others edit my Photos:
    Photos OK to edit
    The basic rule I use is to edit the files from the camera. If you are mixing files in a project then I can see transcoding to the same format if your computer does not have the power to edit. I rarely have a problem mixing files in PrPro. I don't know of any cheat sheet on conversions. That is correct that MP4 is a container and contain many, many types of codecs. G-Spot is a good free utility if you are having problems with a file. When you convert files you will lose some quality each time. Depending on your destination will determine your export settings of a project. For instance I had my daughter's wedding project shot in 1080i from 2 Canon HV30's & GoPro 720p. I edited it in 720p composition since the HV30's were 1080 x 1440. Saved the finished project by chapters as HD 720p, transcoded h.264 for Vimeo, and finally downconverted to SD Widescreen for DVDs. Three outputs for three types of viewing.

    If you are getting different types of formats for one project then you have decide which one you want to set up your project. Some may have to be converted to an edit friendly format. There is no one format to fit all occasions. For upload to Vimeo or YouTube my settings: h.264, 1920x1080, Progressive, 29.97 fps, VBR 2 pass encoding, bit target 15Mbps, max 15Mbps. I have my own formula when I down-convert to SD Widescreen DVD which I rarely do anymore.
     
  4. rocketcityman

    rocketcityman TPF Noob!

    Joined:
    Jan 12, 2018
    Messages:
    12
    Likes Received:
    0
    Can others edit my Photos:
    Photos NOT OK to edit
    Thank you for the helpful feedback.

    Two questions relating to some things you said:

    - First, although I assumed something like "[w]hen you convert files you will lose some quality each time" was indeed the case, aside from that possibly not always being the case if only the container is changing but the codec & resolution remains the same (in which case the video content is not encoded at all but "unzipped" and copied to the new container format I believe), one thing I would like to know is a ranking system of least-lossy to most-lossy codecs. That way I could determine (professionally speaking) when it is already "too late" if a source video handed to me from someone else is in a very poor format or has been transcoded "one too many times" (as you were alluding to) before it reaches me.

    I don't know why but I tend to cringe when I'm given AVI files. Perhaps this is in part because of the massive file size of most of the ones I've seen, relative to their MP4/H.264 equivalents, though I'm not sure what codec AVIs most commonly use. They seem clunky & slow in editors and I associate it with an out-of-date format (literally also 640x480 video comes to mind when I hear "AVI", though I'm sure it can handle high-res). Apparently WMVs, by comparison, aren't too much of a problem though since the VC-1 codec they are commonly paired with is used by other container formats as well.

    - Secondly, as for down-converting to SD for Widescreen, are you just referring to things like reducing resolution and bitrate, because as I recall DVDs use the MPEG2 standard, yet Blueray also uses MPEG2 just with a higher resolution and it looks great. I confess to not knowing much about what role bitrate plays in video quality though. In any case, can't high-res MPEG2 be used as a good delivery medium as well?

    Thanks!
     
    Last edited: Jan 30, 2018
  5. CherylL

    CherylL TPF Supporters Supporting Member

    Joined:
    Aug 6, 2012
    Messages:
    956
    Likes Received:
    616
    Location:
    near St Louis
    Can others edit my Photos:
    Photos OK to edit


    The AVI file has much more information than a WMV. A WMV is a delivery compressed format. This a great video on formats & codecs. As a note, when he refers at the beginning and at the ending about an editing format he is using it as a proxy file. On export the editor will use the original file that has all of the info. Your editor may or may not support using proxy. Personally I do not use a proxy file. This video tutorial explains bit rates too.

     

Share This Page