<p>The best compression would come from a <a href="http://en.wikipedia.org/wiki/Variable_frame_rate" rel="nofollow">variable frame rate</a> format.  Variable Frame Rate formats are designed to adjust their frame rate based on the level of activity in the video.  For something with a very low effective framerate, this would allow it to store the image far fewer times and simply describe how long the image should stay up for.  It would then use more frames when necessary for any transitions.</p>

<p>The one downside to variable framerate formats is that there aren't a whole lot of well supported ones and even fewer good encoders to support working with them, but it is what would give the best results.</p>

<p><a href="https://trac.handbrake.fr/wiki/VariableFrameRate" rel="nofollow">Handbrake</a> appears to support VFR output.</p>

CC BY-SA 3.0
2014-01-27T18:54:00.103Z
Thank you. I see here http://en.wikipedia.org/wiki/Comparison_of_container_formats that MP4 and OGG both support VFR. Is this automatic, or does it have to be configured, or is it dependant on the authoring software, or what? I have never authored a video, and am kind of clueless. I am fine with it not being well supported. I only need this to play on a few controlled computers, where I can install whatever player is needed.
Baruch
CC BY-SA 3.0
2014-01-27T19:12:47.977Z
@baruch - it would probably be automatic, but it would depend on the encoding software you used.  I'm not familiar with any particular encoders for doing this.  I've mostly seen it coming from low power cellphone cameras that need to use simpler compression, but it also happens to be useful for what you are trying to do.
AJ Henderson
CC BY-SA 3.0
2014-01-27T15:50:24.440Z
2014-03-19T22:21:08.540Z
2014-03-19T22:21:08.540Z
AJ Henderson
<p>Most video codecs lets you control the interval of what's called keyframes (or intra frames). Those are snapshots of the video, of which the codec will then try to interpolate lost data between. If you only need the image to change every x seconds, and you are OK with 1 second distortion/tween/morph/artifacts then simply set the keyframes interval to 1.</p>

<p>I'm not an expert (never tried what you want to do) but I think H.264/MPEG-4 would be a good match. Hope this helps!</p>

<hr>

<p>If you have access to the player (if this is for an app you're making, or a website etc), you could try to mimic this behavior using just an image viewer for your platform and an audio player.</p>

CC BY-SA 3.0
2014-01-27T15:04:33.043Z
Keyframe interval is generally not the number of seconds between frames, but rather the number of frames.  If you put a keyframe interval of 1, then the video is going to be all keyframes.  This is the opposite of what they are looking for.
AJ Henderson
CC BY-SA 3.0
2014-01-27T13:35:57.643Z
2014-01-27T13:35:57.643Z
AlexanderBrevig
<p>What would be the best (e.g. most compact) format for a "video" that is actually an audio track with a single static image the whole time? (<a href="https://www.youtube.com/watch?v=FHfIfGlNrx4" rel="nofollow">example</a>)</p>

<p>And if it was not one static image, but a slow slideshow (maybe 1 image every couple of minutes)?</p>

<p><strong>EDIT</strong><br>
One more case: What if it is a short clip (1-2 seconds), that itself is full quality (I think that means 25 FPS, right?), but is played in a continuous loop throughout the entire audio?</p>

CC BY-SA 3.0
2014-01-27T11:05:10.537Z
I didn't realize that when I post a link to youtube, it will embed the video. How do I make it just a regular link?
Baruch
CC BY-SA 3.0
2014-01-27T13:18:30.183Z
Figured out how to link to youtube.
Baruch
<file-formats><compression>
Best format for audio track with a single/few images
Baruch
# Best format for audio track with a single/few images

(Asked by: username_0 on 2014-01-27)

What would be the best (e.g. most compact) format for a "video" that is actually an audio track with a single static image the whole time? ([example](https://www.youtube.com/watch?v=FHfIfGlNrx4))

And if it was not one static image, but a slow slideshow (maybe 1 image every couple of minutes)?

**EDIT**  
One more case: What if it is a short clip (1-2 seconds), that itself is full quality (I think that means 25 FPS, right?), but is played in a continuous loop throughout the entire audio?

**Tags:** file-formats, compression

> **Comments:**
> **username_0**: I didn't realize that when I post a link to youtube, it will embed the video. How do I make it just a regular link?  
> **username_0**: Figured out how to link to youtube.  

---

## 2 answers

### Answer by username_1 on 2014-01-27. Score: 1 | Accepted answer

The best compression would come from a [variable frame rate](http://en.wikipedia.org/wiki/Variable_frame_rate) format. Variable Frame Rate formats are designed to adjust their frame rate based on the level of activity in the video. For something with a very low effective framerate, this would allow it to store the image far fewer times and simply describe how long the image should stay up for. It would then use more frames when necessary for any transitions.

The one downside to variable framerate formats is that there aren't a whole lot of well supported ones and even fewer good encoders to support working with them, but it is what would give the best results.

[Handbrake](https://trac.handbrake.fr/wiki/VariableFrameRate) appears to support VFR output.

> **Comments:**
> **username_0**: Thank you. I see here http://en.wikipedia.org/wiki/Comparison_of_container_formats that MP4 and OGG both support VFR. Is this automatic, or does it have to be configured, or is it dependant on the authoring software, or what? I have never authored a video, and am kind of clueless. I am fine with it not being well supported. I only need this to play on a few controlled computers, where I can install whatever player is needed.  
> **username_1**: @baruch - it would probably be automatic, but it would depend on the encoding software you used.  I'm not familiar with any particular encoders for doing this.  I've mostly seen it coming from low power cellphone cameras that need to use simpler compression, but it also happens to be useful for what you are trying to do.  

---

### Answer by username_2 on 2014-01-27. Score: -1

Most video codecs lets you control the interval of what's called keyframes (or intra frames). Those are snapshots of the video, of which the codec will then try to interpolate lost data between. If you only need the image to change every x seconds, and you are OK with 1 second distortion/tween/morph/artifacts then simply set the keyframes interval to 1.

I'm not an expert (never tried what you want to do) but I think H.264/MPEG-4 would be a good match. Hope this helps!

---

If you have access to the player (if this is for an app you're making, or a website etc), you could try to mimic this behavior using just an image viewer for your platform and an audio player.

> **Comments:**
> **username_1**: Keyframe interval is generally not the number of seconds between frames, but rather the number of frames.  If you put a keyframe interval of 1, then the video is going to be all keyframes.  This is the opposite of what they are looking for.  

---

