Newsgroup: it.media.video.produzione
Titolo: dropped frames

Ciao a  tutti,
l'argomento è stato più volte affrontato su questo NG
ma nonostante abbia letto molti post vecchi non riesco
a risolvere il problema.
Ho provato con vari sw ma i dropped frames sono veramente
tanti....
Ho una macchina vecchia (PIII 650 MHz e win 2K ) ma
ho già fatto un riversamento in passato senza problemi
  a parte per il tempo del rendering ;-)
Che possa essere un problema della telecamera (testino sporche)?
Ho notato con il task manager un uso intenso della cpu, il trasferimento
se non sbaglio non dovrebbe richiedere molte risorse....
Ovviamente non ci sono altre applicazioni attive...
Qualche suggerimento?!
Ciao e grazie!
Nicolò

 Qualche suggerimento?
Hai provato AVI_IO?
Perchè quello ti avverte se si svuota il buffer e allora sai se il tuo
sistema ce la fa o no.


Ho fatto la prova e AVI_IO non mi ha dato nessun messaggio dei errore,
però il file avi è disturbatissimo e si vede pure a scatti...
A questo punto potrebbe essere la telecamera? Però collegandola
alla tv non vedo disturbi ma forse non c'entra nulla?
Grazie
Nicolò

 A questo punto potrebbe essere la telecamera?
No

 
mmm vedo cosa posso fare
Ciao

 tramite firewire, non mi sembra si debba settare qualcosa o sbaglio ?
Ecco, c'era qualcosa che non mi tornava!
Comunque AVI_IO gestisce anche il formato DV via driver WDM.
Currently AVI_IO supports OHCI compliant boards or any other DV board as
long as there is a Video for Windows capture driver installed for it, or a
working WDM DirectShow wrapper. The support is currently limited to
capturing only and also does not include device controlls. Boards known to
work well are the ADS Pyro, the Exsys, SIIG and Pinnacles Studio DV. You
need Windows 98SE or Windows 2000 or better, since only those platforms have
a working WDM wrapper. Note the following information is important to make
AVI_IO work wiht DV devices.
The camcorder must be turned on and transmitting a DV datastream to the
computer before you start up AVI_IO. To achive this with some camcorders you
must set them to VCR mode, and hit "Play"
If AVI_IO seems to freeze, make sure the camcorder is sending DV Data. Note,
this is a limitation of the WDM Video for Windows wrapper and not a
limitation of AVI_IO
You must set the propper framerate under capture settings (29.97 fps for
NTSC, 25fps for PAL)
It does not matter what audio format you choose or if you have configured
one already. AVI_IO will adapt the audio format to the one it finds on tape.
If AVI_IO detects a frame which is having a different audio format than the
previous one, the capture stops. You can then continue from this spot with a
new capture. This is because it's not possible to change the audio format in
an avi file "on the fly".
There is no preview visible if you don't have a Video for Windows DV codec
installed in your system. Preview is not needed to capture DV video with
AVI_IO. A DV codec known to work well is the one available from Mainconcept
If you run out of I/O buffers, or if the captured video is jerky or is
having crackly sound, turn off preview and use your camcorders display to
monitor the capture. This frees up a significant amount of CPU resources
which otherwise may lead to the described behaviour.
Using the mentioned DV codec from Mainconcept it's even possible to capture
from analog sources into DV format in realtime using AVI_IO. You need a
700Mhz or faster processor for it and an analog capture device which is
supporting the DV resolution for captures (most TV tuner boards will do).
This is having the advantage, that older analog footage does not have to be
rendered in the NLE application if it's used along with DV footage.
12-bit audio as it's available with most DV devices is translated into 16
bit 32kHz audio during capture since the PC usually does not understand 12
bit audio.
A personal not with regard to 12-bit audio. With camcorders it does not make
sense in most cases to use 12 bit audio. 12 bit audio is here to support
four audio channels which usually can't be recorded with a camcorder. Since
there is a reserved amount of space per frame in the DV data stream for the
audio, the space will be used up anyways, so you don't get more recording
time or a faster data transfer by limiting yourself to 12 bit audio. I
recommend to always record with the best audio format available (48kHz
16-bit stereo)

Il problema rimane farò delle prove su un'altro pc.
Grazie
Nicolò
Elio wrote:
Cut

 
Risolto finalmente!!!
Era un problema del driver ide, il disco nonera abbastanza veloce nel 
scrivere i dati.
Ho riversato due ore di filmato e zero dropped frames wow :-)
Nicolò