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Can they be used exactly like gifs? I have seen a few sites with mp4s but Firefox blocks them. I do not think even sites like Dribbble have figured it out. I h

by capybara_2020 5y ago

Can they be used exactly like gifs? I have seen a few sites with mp4s but Firefox blocks them. I do not think even sites like Dribbble have figured it out. I have a lot of issues there with videos.

astroalex 5y ago
I have issues with videos on Twitter. It's not every video, but about 10% refuse to play in Firefox.
devmor 5y ago
Firefox doesn't block any MP4s for me. Sounds like your addons, or a cross site security error.
hateful 5y ago
Maybe they had sound, even if it was silence? https://support.mozilla.org/en-US/kb/block-autoplay https://support.mozilla.org/en-US/kb/block-autoplay
gpvos 5y ago
In what way does Firefox block them? If you mean they don't autoplay: that is how it is meant to be. Please do not annoy your users.
- mceachen 5y ago
  They may have tried to open arbitrary mp4s and had Firefox not render it. Firefox seems to only render MP4 files that use yuv colorspace and aa3 audio channels, which require specific ffmpeg flags during transcoding. It took me a day of grinding whackamole to find the magic set of arguments to make all recent, popular browsers actually display a video: https://github.com/photostructure/photostructure-for-servers/blob/1f6d907769fd2b01900eb88ce64bf0d732998aa0/defaults.env#L783 https://github.com/photostructure/photostructure-for-servers...
  - Groxx 5y ago
    Possibly a useful doc for ya then: https://developer.mozilla.org/en-US/docs/Web/Media/Formats/Video_codecs#recommendations_for_everyday_videos https://developer.mozilla.org/en-US/docs/Web/Media/Formats/V... . And beyond that it depends on the OS, so windows/linux/mac/ios/android/etc will all vary. Some of this is also probably due to using ffmpeg directly, tbh. It's very happy to produce irrational combinations of things that are technically allowed by specs but not implemented anywhere in practice, often exacerbated by it trying to preserve metadata / colorspace / etc where technically possible.
  - Sesse__ 5y ago
    More specifically, most devices will want _4:2:0_ Y'CbCr. It's highly unlikely that FFmpeg gave you anything that's not Y'CbCr (H.264 can technically encode RGB, but I've never ever seen it in use). And if it chooses 4:2:2 or 4:4:4, you get a warning. FWIW, if you really want to encode your video in Rec. 2020, you'd almost certainly want a 10-bit encode, and then you're outside what e.g. iOS devices will render again. Rec. 709 is the safe choice.
marcosdumay 5y ago
Well, Firefox blocks gifs to me too. It depends on how you configure it. Any option you choose, make sure the first frame is informative.
- chrisseaton 5y ago
  The vast vast majority of people don't configure their browsers at all. What matters is what the defaults are.
  - marcosdumay 5y ago
    By default Firefox blocks anything that has audio, and lets anything that is mute play. In fact, now that I searched it again, it seems that there is no option to make gifs behave differently from video files anymore. That's not what the GP saw.

Can they be used exactly like gifs? I have seen a few sites with mp4s but Firefox blocks them. I do not think even sites like Dribbble have figured it out. I have a lot of issues there with videos.

astroalex 5y ago

I have issues with videos on Twitter. It's not every video, but about 10% refuse to play in Firefox.

devmor 5y ago

Firefox doesn't block any MP4s for me. Sounds like your addons, or a cross site security error.

hateful 5y ago

Maybe they had sound, even if it was silence? https://support.mozilla.org/en-US/kb/block-autoplay https://support.mozilla.org/en-US/kb/block-autoplay

gpvos 5y ago

In what way does Firefox block them? If you mean they don't autoplay: that is how it is meant to be. Please do not annoy your users.

mceachen 5y ago
They may have tried to open arbitrary mp4s and had Firefox not render it. Firefox seems to only render MP4 files that use yuv colorspace and aa3 audio channels, which require specific ffmpeg flags during transcoding. It took me a day of grinding whackamole to find the magic set of arguments to make all recent, popular browsers actually display a video: https://github.com/photostructure/photostructure-for-servers/blob/1f6d907769fd2b01900eb88ce64bf0d732998aa0/defaults.env#L783 https://github.com/photostructure/photostructure-for-servers...
- Groxx 5y ago
  Possibly a useful doc for ya then: https://developer.mozilla.org/en-US/docs/Web/Media/Formats/Video_codecs#recommendations_for_everyday_videos https://developer.mozilla.org/en-US/docs/Web/Media/Formats/V... . And beyond that it depends on the OS, so windows/linux/mac/ios/android/etc will all vary. Some of this is also probably due to using ffmpeg directly, tbh. It's very happy to produce irrational combinations of things that are technically allowed by specs but not implemented anywhere in practice, often exacerbated by it trying to preserve metadata / colorspace / etc where technically possible.
- Sesse__ 5y ago
  More specifically, most devices will want _4:2:0_ Y'CbCr. It's highly unlikely that FFmpeg gave you anything that's not Y'CbCr (H.264 can technically encode RGB, but I've never ever seen it in use). And if it chooses 4:2:2 or 4:4:4, you get a warning. FWIW, if you really want to encode your video in Rec. 2020, you'd almost certainly want a 10-bit encode, and then you're outside what e.g. iOS devices will render again. Rec. 709 is the safe choice.

marcosdumay 5y ago

Well, Firefox blocks gifs to me too. It depends on how you configure it. Any option you choose, make sure the first frame is informative.

chrisseaton 5y ago
The vast vast majority of people don't configure their browsers at all. What matters is what the defaults are.
- marcosdumay 5y ago
  By default Firefox blocks anything that has audio, and lets anything that is mute play. In fact, now that I searched it again, it seems that there is no option to make gifs behave differently from video files anymore. That's not what the GP saw.