pirata
6th December 2002, 18:53
Hi everybody.
I am an engineer currently based in France. I have a ADSL connection and I thought I could enjoy a tighter and warmer contact with my relatives and old firends in Germany using a Webcam and a Netmeeting-like program. Unfortunately I haven't ever had any experience with this kind of hardware/software, so I need some insight from the savvy people before using the Visa.
Many of my relatives and my friends are also getting into the mood for webcamming, but we all agree that good quality is a must for really having a warn and nice webcam experience. Most webcam demonstrations I have seen were 384x288-15fps, even using 128/256 ADSL.
The problem can be divided into parts (if any of my statements is not true, don't hesitate to tell me so):
1-the captured video and audio are sent down to the PC via USB1.0, in UNCOMPRESSED format. That really eats up the USB bandwidth and limits the video quality you can get. I think usual resolutions are somewhere near 384x288 at 15fps. Correct me if I am worng, please.
I guess it is impossible to implement any kind of hardware compressor in the webcam (not even the simplest ones, as Huffyuv or MJPEG), so the only solution here is USB2.0. Are there already USB2.0 webcams? Could anybody of you tell me which video stream specs are achievable with these newer devices?
2-Once you get the video in the PC, you want to stream it to your mate in the other country. It is necessary to compress it first, though. And here begins the second problem: you need realtime video and audio codecs that are able to squeeze the data to fit in a little bit less than 128kbs. And you also need a streaming application that is able to interface with those codecs and stream their outputs. This streaming application should also be able to store the incoming data in HD (for later reviewing) and also allow to chat with 2 mates at the same time (since the down stream rate is 256 in ADSL, which provides for 2 inbound streams and one outbound stream).
As for realtime codecs I've found dicas mpegable codec (look for it in the web). Although it is MPEG4 (good quality at low bitrates), the image size is no bigger than 384x288. I don't know of any other realtime codec (MJPEG codecs and similar stuff can't do a great job at compressing). I also don't know of streaming apps interfacing with user-selected codecs.
Well! That's a starting point. I can hardly wait for your contributions!
Cheers, Marc
I am an engineer currently based in France. I have a ADSL connection and I thought I could enjoy a tighter and warmer contact with my relatives and old firends in Germany using a Webcam and a Netmeeting-like program. Unfortunately I haven't ever had any experience with this kind of hardware/software, so I need some insight from the savvy people before using the Visa.
Many of my relatives and my friends are also getting into the mood for webcamming, but we all agree that good quality is a must for really having a warn and nice webcam experience. Most webcam demonstrations I have seen were 384x288-15fps, even using 128/256 ADSL.
The problem can be divided into parts (if any of my statements is not true, don't hesitate to tell me so):
1-the captured video and audio are sent down to the PC via USB1.0, in UNCOMPRESSED format. That really eats up the USB bandwidth and limits the video quality you can get. I think usual resolutions are somewhere near 384x288 at 15fps. Correct me if I am worng, please.
I guess it is impossible to implement any kind of hardware compressor in the webcam (not even the simplest ones, as Huffyuv or MJPEG), so the only solution here is USB2.0. Are there already USB2.0 webcams? Could anybody of you tell me which video stream specs are achievable with these newer devices?
2-Once you get the video in the PC, you want to stream it to your mate in the other country. It is necessary to compress it first, though. And here begins the second problem: you need realtime video and audio codecs that are able to squeeze the data to fit in a little bit less than 128kbs. And you also need a streaming application that is able to interface with those codecs and stream their outputs. This streaming application should also be able to store the incoming data in HD (for later reviewing) and also allow to chat with 2 mates at the same time (since the down stream rate is 256 in ADSL, which provides for 2 inbound streams and one outbound stream).
As for realtime codecs I've found dicas mpegable codec (look for it in the web). Although it is MPEG4 (good quality at low bitrates), the image size is no bigger than 384x288. I don't know of any other realtime codec (MJPEG codecs and similar stuff can't do a great job at compressing). I also don't know of streaming apps interfacing with user-selected codecs.
Well! That's a starting point. I can hardly wait for your contributions!
Cheers, Marc