[mythtv-users] Hardware transcode

[Nick Rout]

On Wed, Oct 24, 2012 at 4:41 AM, Gary Buhrmaster
<gary.buhrmaster at gmail.com> wrote:
> On Tue, Oct 23, 2012 at 4:54 AM, Josu Lazkano <josu.lazkano at gmail.com> wrote:
>> Hello, I have a low power backend, so I can't make transcode of the
>> recordings. I want to know if it is possible to attach any hardware
>> device (USB, PCI, PCIe...) to the backend to make a hardware
>> transcode.
>>
>> I look for the Elgato Turbo.264 HD:
>> http://www.elgato.com/elgato/na/mainmenu/products/Turbo264HD/product1.en.html
>>
>> Someone have any experience with this device on Linux machines?
>>
>> Best regards.
>
> This question has come up before.  Support would have to be from
> ffmpeg, and last I knew the patch(es) to support this device have
> not made it into that code base (and therefore not into the port of
> ffmpeg to MythTV).
>
> This is no different than support for NVENC, QuickSync, VCE, or
> a number of other hardware encoders.  Look to the ffmpeg or
> libav teams for support.  MythTV just takes advantage of their
> improvements (and, unfortunately, gets their new bugs too)
> when it pulls in the later versions of ffmpeg.
>
> Note that some individuals have a strong opinion regarding
> the quality of the resulting h264 encoding with these hardware
> options, which tends to influence their integration plans and
> schedules.
>
> Gary

Frankly you only need to read endorsements like "I'm floored by the
speed at which it processes HD files. Simply stunned. The only
satisfactory way i'd found to successfully convert HD .mkv files to
.mp4 was using compressor and it often took up to 48 hours.. that's
right, two days... and even then the sound was stereo. Now I can do it
in just over twice realtime and keep the AC3 sound... I'm very, very
impressed" to see that this particular reviewer doesn't even
understand the difference between a container and a codec, not to
mention the difference between video and audio. FFS, it makes me
suspect all of the reviews on their page.

(for the uninitiated mkv and mp4 are container formats, both can
contain h.264 video streams. Most .mkv files you'll find do in fact
have h.264 video in them and in that case to convert from an mkv
container to a mp4 container is pretty trivial in computing resource
terms. I won't even go into the audio issues. Sheesh)