Re: dvgrab wait for device

On Mon, Jun 29, 2009 at 7:52 PM, Dan Dennedy<[email protected]> wrote:
> On Mon, Jun 29, 2009 at 11:16 AM, Carl Karsten<[email protected]> wrote:
>> On Mon, Jun 29, 2009 at 12:41 PM, Dan Dennedy<[email protected]> wrote:
>>> On Mon, Jun 29, 2009 at 7:35 AM, Carl Karsten<[email protected]> wrote:
>>>> if there is no device when dvgrab is first run, it aborts.  Yet if it
>>>> is streaming I can unplug the device and plug it back in, and the
>>>> stream continues.  If there were some way to get dvgrab to just wait
>>>> for a device, that would be great.  Or if someone can replace the
>>>> execvp(dvgrab with the C code from dvgrab... then I can take that off
>>>> my list of things to look into :)
>>>
>>> Hmm, well, there can be multiple Firewire buses on your system, and
>>> dvgrab looks for a device across all the buses to see which bus to
>>> use, which is required to acquire a  libraw1394 handle. You would have
>>> to add some loop around that with a limited retry.
>>
>> Would it help if this was limited to being told what -card was in use?
>>  or guid, or something to avoid the scan?
>
> It should work today using -card and -noavc, but it will time out
> waiting for DV after 10 seconds. Thiis timeout is a feature. Do you
> need AV/C

Nope.  one of the args is:
    *argp++ = "-noavc";

>  and what do you want to do about this timeout?

how about
--timeout 0

Looks ilke this is the place...  tomorrow I will take a shot at tweaking it.


        // Wait up to N seconds to see if we got any data
        // this is a little unclean, checking global g_done from
main.cc to allow interruption
        while ( !g_done && m_frame == NULL && tryCounter-- > 0 )
        {
                timespec t = {0, 25000000L};
                nanosleep( &t, NULL );
        }

        // OK, we have data, commence capture
        if ( !g_done && m_frame )
        {
                sendEvent( "Capture Started" );
                m_captureActive = true;
                m_total_frames = 0;

                // parse the SMIL time value duration
                if ( m_timeDuration == NULL && ! m_duration.empty() )
                        m_timeDuration = new SMIL::MediaClippingTime(
m_duration, m_frame->GetFrameRate() );

                if ( m_dst_file_name )
                        pthread_mutex_unlock( &capture_mutex );
        }

        // No data received in N seconds, throw an error
        else if ( !g_done )
        {
                if ( m_dst_file_name )
                        pthread_mutex_unlock( &capture_mutex );
                const char *err = m_hdv ? "no HDV. Try again before
giving up." : "no DV";
                if ( m_hdv )
                        reset_bus( m_port );
                throw std::string( err );
        }
        else
        {
                if ( m_dst_file_name )
                        pthread_mutex_unlock( &capture_mutex );
        }

-- 
Carl K

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