Work at SourceForge, help us to make it a better place! We have an immediate need for a Support Technician in our San Francisco or Denver office.

Close

Container/Stream variations? Are they really different?

dandirk
2013-01-03
2013-01-03
  • dandirk
    dandirk
    2013-01-03

    Ok I know this sounds anal, but that is how I role...

    Currently using mediainfo to gather sample media files to build/test a universal media player at work (sick and tired of every user/tech installing 100 players when only 1 is needed lol).

    I have found files that are similar but listed slightly different in MediaInfo. Either the Container or one of the streams will be just slightly different. Common are different extension of the file, or variations of a container usually listed inside of () like "MPEG-4 Visual (Divx 5)".

    Below are a couple of examples, of files I think are pretty much the same, for my purposes testing player/codec playback and functionality.

    How different should I be treating these "variations"? Will a "MPEG-4 Visual (Divx 5)" video stream generally use the exact same codec as a normal "MPEG-4 Visual"? So if I were gathering sample/test media, I would realistically only need one example of MPEG-4 Visual video stream?

    I know extensions aren't specifically tied to a container, though in many cases extensions will match the container being used (or many ext will use one container etc). Should I even be concerned with file extensions (besides file/app association)? From my limited knowledge codecs/players generally use the container/stream for support so you could open a renamed media.txt file and it would play if codecs are supported?

    Thanks for you help.

    EXAMPLE #1

    File 1 (.mov)
    Container: MPEG-4 (Quicktime)
    Video: AVC
    Audio: AAC

    File 2 (.m4v)
    Container: MPEG-4
    Video: AVC
    Audio: AAC

    EXAMPLE #2

    File 1 (.3pg)
    Container: MPEG-4 (3GPP Rel 5)
    Video: MPEG-4 Visual
    Audio: AMR

    File 2 (.m4v)
    Container: MPEG-4 (3GPP Rel 5)
    Video: MPEG-4 Visual
    Audio: AMR

     
  • Below are a couple of examples, of files I think are pretty much the same, for my purposes testing player/codec playback and functionality.

    They are "pretty", but are not same. And this MAY be an issue.
    Welcome in the wonderful workd of video.

    Should I even be concerned with file extensions

    No. Else the player is a very bad player (sometimes STB are not very good)

    From my limited knowledge codecs/players generally use the container/stream for support so you could open a renamed media.txt file and it would play if codecs are supported?

    Yes (if the player has a good design)

    "MPEG-4 Visual (Divx 5)".

    I don't see what you are speaking about.
    If you speak about Codec IDs, the problem is the support of the Codec ID list from the player. one file MAY not be supported, only because 4 bytes in the file (the Codec ID) is unknown. For MPEG Visual, there are tens of different codec ID, without any official list. You need the ten files when you test all the players... In case one player has not one Codec ID in its list.

    Container: MPEG-4 (Quicktime)
    Container: MPEG-4

    Different: the header has some slightly differences, most players handle both but some player can handle only one of the them (the standard one or the apple version). Same dor 3GPP, it is anohter specification, pretty the same, but not exactly the same.

    EXAMPLE #2

    Same except the file extension. If the player is well made, it does not rely on the file extension.