[mythtv-users] Mythexport sssssllllllloooooooowwwwww

[Greg Oliver]

On Tue, Aug 31, 2010 at 3:36 AM, Diego Torres <torres.diego at ttcpl.com.au> wrote:
> Hi,
> Until recently I had no need to use mythexport. I got an Ipad last week and
> decided to go ahead and try this feature.
> I have managed to get it working but it is extremely slow. It takes about 6
> times longer than the recording it is converting.
> I have installed the airvideo server (via wine not the native linux one) and
> converting the same file it takes 1/2 the time
> of the recording.
> For example:
> Program : Monster Moves AUG 28
> Format :HD 720P
> Size in Myth :1 hour  5 minutes (4.9GB)
> time to convert in myth export: 7 hours (and then I cancelled)
> size mythexport: 657 MB when cancelled
> time airvideo : 36 Minutes
> size export airvidieo: 537MB
>
> The machine is a VM running on Citrix Xen Server 5.5 and has been configured
> with 4 CPUS, 1 GB of ram and 500 GB of HDD space.
> The Underlying CPU is an Intel Core 2 Quad Q9400 @ 2.66GHz.
> I understand that both mythexport and airvideo use ffmpeg (as far as it is a
> requirement for both) so I am not sure what the difference could be.
> However I noticed the following:
> 1. Myth took about 3 hours to actually start writing the converted file.
> During that time the two companion files xxx264.xxx. and ffmXXX.XX were
> being
> populated.
> 2. When Mythexport was doing the conversion ffmpeg was running at 100% on
> only one core. It would jump around cores every 10 minutes or so
> but it never used two cores at the same time. As a result the total CPU
> usage was always < 25%.
> 3. When Airvideo was doing the conversion all 4 cores ran at  ~80%  for the
> whole 36 minutes.
>
>
> INFO ON THE MYTH SETUP
> Version :  Mythbuntu 9.10 which was upgraded to 10.4LT by upgrading Ubuntu,
> enabling the myth repos and enabling 0.23.1 as the target version
> MythExport:  Hacked the script file (can't remember the name) to use libfaac
> instead of lamemp3 (so that I could sync the files with Itunes)
> The conversion job is configured as follows
> - Resolution : 704*576
> -Aspect: 16:9
> -Audio rate: 192kb
> -Video rate: 1800kb
> -Codec: h264
> - Remove commercials= yes
> -Audio channels: 2
> The job is not setup to run automatically. I run it by showing the recording
> details in mythweb and then clicking on the third Job "Convert to Ipod" that
> I setup
> Why those conversion settings? I did a test run with the same setting except
> the video rate was at 600Kb. It was a standard def file and only 29 minutes
> long. The output looked good on an iphone but too pixelated on the ipad. I
> converted the same file using handbrake (on a different computer so I wasn't
> comparing conversion times) with the "universal" preset which looked great
> on the ipad. I checked the file's details and the only difference with the
> mythexport one was the video rate so I changed that in mythexport.
>
> I rather use mythexport for the file/job management capabilities but at
> those speeds It is useless for converting files on a regular basis.
> Any suggestions will be greately appreciated.
>

I am going to take a stab here since you did not provide any concrete
info..  The original recording is 264?