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Help Streaming from a USB device

whs37

whs37

Android Enthusiast
I have been trying to stream .mp4 videos from a USB stick and from a USB attached SSD. It plays - kind of. But it is not fluent and crackles all the way after it started correctly for a few seconds.

Especially the SSD I expected to work because that is a really fast device with access times of under 0.1ms - which is appr. 150 times faster than for a spinning disk.

Any idea what could be the problem.

Since videos take a lot of storage space, I did not want to stuff my N7 storage with them. They play well when they are on the SSD storage though. But since the SSD is probably faster than the internal storage, there must be a lot of delay with the USB attachment.
 
The USB storage might be too slow for the video, depending on how large the video is, how fast the USB drive is...etc. Considering it plays fine on the internal memory, there is definitely a bottleneck on the USB stick side.
 
I don't think the SSD is too slow. It is the fastest external device you can think of. But I think you are right. The bottleneck must be the USB channel. It must be a lot slower than on a PC which is 480MB/sec.
 
I think it also has to do with the format you are using. I was using avi as they were of nice high quality but they did the same thing. So I converted them to mp4 format with Handbrake and they work just fine now from a USB.
 
USB is 480Kbps not MBps or about 12-20MBps typical read speeds into a PC
bits per second small b not Bytes per second with cap B

Look at the converted video bit rate to know if it will play well. I handbraked a couple of old b&w movies and had really different rates using the same format mp4.
 
JanComputerman said:
USB is 480Kbps not MBps or about 12-20MBps typical read speeds into a PC
bits per second small b not Bytes per second with cap B

Look at the converted video bit rate to know if it will play well. I handbraked a couple of old b&w movies and had really different rates using the same format mp4.
Click to expand...
Right, sorry my typo.
 
I am able to stream MP4's from SD cards and microSD cards thru a USB card reader attached to an OTG cable using Nexus Media Importer without any static or stuttering. Maybe the USB port on the Nexus 7 doesn't provide enough power for the ssd. Have you tried running the ssd from a powered hub attached to the OTG cable?

BTW, the speed of USB 2.0 is neither 480Kbps nor 480MBps but is 480Mbps (megabits not megabytes).
 
Now we really srewed it up good. It is, of course, 480Mbps/sec. An old man can get all confuded with the big 'B's' and little 'b's', LOL. I fixed it in my original post.

Regarding the power drain - the SSD uses very little power. Probably less than a stick. I will try again with a faster stick. Too bad that USB3 is not supported because I would have one of those sticks.

The framerate of the videos is 25 and 30 frames/sec. So that should not be the problem.
 
Oops! after effects of anesthesia! DUH! Of course it is with typical 26 MBps data speeds it is at least 10 x faster bit rate speed. I have seen the 5,000 Mbps rate that is referring to USB 3.0 in the wikipedia and wow is that fast. I did a windows 7 backup to a USB 3.0 SSD drive at 120 Mega Bytes a second!

USB 2.0 1.5/12/480/5,000 Mbit/s (depending on mode)
 
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