Really hoping somebody can help me, I have hundreds of videos of my children from a young age and it seems a good selection of these are now unable to play.
This is a situation in which you must help yourself by analyzing the files and posting back with more information in order to receive suggested solutions or post examples of the files for someone else to analyze. Basically there are three facets to consider—the codecs used to create the contents, the file container in which the data is stored, and how the player being used is programmed to recognize/play the files.
1) If a file will not open in any media player, then use the Finder "Info" window or a dedicate app like MediaInfo to get encoding information as depicted below.
Finder "Info" Window Examples:
MediaInfo Examples:
2) If a file will open in a media player app but has a playback problem (e.g., no audio, no video, only one video track segment is visible and the others display as a black screen, etc.), then open the player "Inspector" and/or "Property" window to learn more about how the file was encoded as depicted below:
QT X Player "Inspector" Example:
QT 7 "Inspector" Example:
QT 7 Pro "Properties" Example:
VLC "Media Information.../Codec Details" Example:
Firstly, some that are on my iPhone if attempted to play will give me the error Unable to Play Video because file format is unsupported. I have then gone onto my iCloud using my laptop to download these exact files and still get the same error on my Mac.
What does "on my iPhone" mean here? Were these files originally recorded on this iPhone? A previous iPhone whose data was moved to the new iPhone? Email attachments "opened" or "copied" to another app? Files that were sync'd by iTunes? Sync'd by a third-party app? So on and so forth. In some cases the file data would be presumed to be MacOS/iOS/tvOS compatible already—implying the file data and/or container is corrupted or the files are so old that software updates consider them a security issue—while in other cases we're relegated back to analysis of codec, container, and/or player incompatibility issues.
I went onto an extrernal hardrive with very old images and videos on, we are literally talking before iCloud was a thing and you had to export all your images every so often to free up space on your phone... years such as 2011, 12, 13 and some of these videos also have the same problem?
One again, how were the files recorded... on what devices and using which codecs? Classic QuickTime has been around for about 27 years. Only going back to 2011 implies that if the files were created on Apple devices or using QT X (which was released in 2009) the file data (if not corrupted) should "normally" be supported if not modified by third-party software that hybridizes profile and level settings for the content.
SO what on earth is going on, has Apple/Quicktime updated so much so and not decided to support these older files?
EVOLUTION! On the one hand, Apple, like many video software purveyors, is transitioning from the "legacy" use of multiple codecs (each having a highly specialized target use) to the use of a relatively small number of highly scaleable "modern" codecs having a very wide range of uses—from video conferencing to UHD videos on optical media. In addition, in an attempt to prevent potential security breaches that may not exist, media player and system updates may sometimes erroneously trap on and refuse fail to load files at may otherwise be fine.
I can't see how I can possibly have corrupt files on icloud and then different corrupt files on my external hardrive - especially when the videos on the hardrive used to play and I haven't touched them and it is different videos not the same videos as what are on my iCloud. It seems too much of a coincidence does it not?
Every time a file is copied or shared there is a potential for corrupting the data or the file container. without knowing the specific workflow used, it is impossible to estimate your particular potential for corruption. Disk operating system characteristics, hardware redundancy, DOS/ISP error correction, power variations, device age, etc. are just a few of the things to be considered here. Without analyzing and/or comparing both the source and copied files, I can't even say if your videos are "the same" (i.e., are byte-for-byte identical) as you indicate.
It may also be worth mentioning that some of these videos exported from icloud are KB's in size?
Not knowing the duration, compression format used, the size of the original source file, or the specific workflow used to upload/download the files—it is impossible to say if this is significant. (E.g., a reference file may only be a few KBs in size but point to hundreds or even thousands of MBs of data and continue to play fine if the referenced data sill exists/is not orphaned but fail to play at all if deleted or orphaned.) Again, someone needs to analyze the file specifics to provide clues the the nature of the problem (or problems) at hand.
I have tried - playing via a VLC and converting the files... I have also tried opening in Adobe After Effect (one or two videos did play, badly, in this program, but not all of them. Others were getting the same not compatible error - making me think if some will play in this program surely they cannot be corrupt?)
Overall, not a good sign. In general, if it won't open in VLC, it is most likely that the file is corrupt or data is missing or orphaned. If the file does open/play in VLC, then chances are excellent you can use HandBrake to convert the files to compression formats that are compatible with any MacOS/iOS/tvOS QT X/7 based app. (I.e., VLC is a great player app for modern and/or "legacy" compression formats but is more of an data streaming pipeline than data conversion app.)
I would really appreciate some help on this matter, I will literally lose hundreds of videos of my children 😟Which is super scary because where can we save these videos if they are not safe on a hardrive that hasn't been touched?
You need to determine if you have more than a single problem here. If you created reference files and then delete the original data files, then this content is probably lost. (I.e., these would be the exceptionally small files.) Files that have a codec support issue ("Video File Format Not Supported") are probably not going to be a problem—other than the time and effort it takes to convert the files to a compatible compression format. Basically, with the release of Mavericks, the modern QT X Player only plays files directly supported by the AVFoundation structure embedded in Mac OS X/MacOS while the QT 7 Player continues to be playback supported by the "classic" QT embed that can use any codec installed by the user. Normally, this isn't a problem for most common "legacy" formats installed on a system since the QT X Player, if it can't play a file, checks with the "Modernizer" embed to see if proprietary or third-part codec support is available/installed on the system to convert the non-playable data to a playback compatible compression format (usually H.264/AAC in an MOV file container). If not, then you get the "Unsupported Format" error message and the file refuses to load. On the other hand, if the required codecs are available, then the data is sent to the "Convert" structure embedded in the operating system which then "attempts" to convert the source file to a compatible format. In most cases, this succeeds but be aware that in some cases (e.g., DTS audio), conversion completes normally but the track is "empty" as far as playback is concerned. Thus, there is no guarantee that this workflow will work every time and is why I normally use HandBrake for such conversions even when the proper "playback" codecs are known to be installed.
