search for: valid_bit

...) I've never tested this, but I designed the jitter buffer to work from two threads even without using a mutex. This would work as long as there is one thread doing the "put" and one thread doing the "get". > As for detecting outages, a hack I use is to check jitter->valid_bits. If > it's set, we decoded "something", if it's not, we're interpolating > something which may not sound that good so feed the soundcard 20ms of > silence instead. Why would you do that. The idea of interpolating a frame is exactly to get better quality than just...

...ll decode and remove from the buffer. Granted, it's not terribly likely to happen, and the jitter-buffer as a whole has no crashbugs regarding two-thread access, but it will sound a bit odd if this should ever happen :) >> As for detecting outages, a hack I use is to check jitter->valid_bits. If >> it's set, we decoded "something", if it's not, we're interpolating >> something which may not sound that good so feed the soundcard 20ms of >> silence instead. > > Why would you do that. The idea of interpolating a frame is exactly to > get b...

...Other than that, I don't think there should be any other possible race (assuming CPU cache coherence). > > Why would you do that. The idea of interpolating a frame is exactly to > > get better quality than just putting zeros. > > Actually, I oversimplified a bit. I check if valid_bits has been zero for > the last 4 frames or more, because once you interpolate more than 100ms > from the last known state, you end up with some weird > blipp-blopp-blooiiing sound. Actually it reminds me of the ambient sound > of weird aliens in bad 50s scifi movies. At that point, s...

Thank you for a very good explanation which shed light on some of the questions that I had after reading the source code. Reading your text however, I wonder if I'm perhaps missing an important point on the proper use of the jitter buffer: ... > Now, clearly, if early_ratio is high and late_ratio is very > low, the buffer is buffering more than it needs to; it will > skip a frame

...values. The chance of this happening is much less than the other one, but it COULD happen ;) >>> Why would you do that. The idea of interpolating a frame is exactly to >>> get better quality than just putting zeros. >> >> Actually, I oversimplified a bit. I check if valid_bits has been zero for >> the last 4 frames or more, because once you interpolate more than 100ms >> from the last known state, you end up with some weird >> blipp-blopp-blooiiing sound. Actually it reminds me of the ambient sound >> of weird aliens in bad 50s scifi movies. At t...

...Speak) -- calling put and get at the exact same time from different threads leads to "features") This allows the jitter buffer to actually buffer, and try to keep the delay between frame arrivel and frame play to a minimum. As for detecting outages, a hack I use is to check jitter->valid_bits. If it's set, we decoded "something", if it's not, we're interpolating something which may not sound that good so feed the soundcard 20ms of silence instead. Incidentally, on Win32 you probably want to use DirectSound with a looping buffer of around 200ms and play notifi...

...32Speak) -- calling put and get at the exact same time from different threads leads to "features") This allows the jitter buffer to actually buffer, and try to keep the delay between frame arrivel and frame play to a minimum. As for detecting outages, a hack I use is to check jitter->valid_bits. If it's set, we decoded "something", if it's not, we're interpolating something which may not sound that good so feed the soundcard 20ms of silence instead. Incidentally, on Win32 you probably want to use DirectSound with a looping buffer of around 200ms and play notifiers;...

...a speed of processing issue? I am seeing a fair number of problem records coming out of the speex jitter buffer, but they might just mean that data isn't being fed in fast enough into the buffer. I'm checking: speex_jitter_get(&speexJitter, (short *)newData, NULL); if (speexJitter.valid_bits == 0) //bad record { fprintf(stderr, "Interpolating since nothing happened!!!!\n"); fflush(stderr); } Does this say I'm processing too slowly into the buffer, or that the data put in is somehow corrupt? The application is Windows based, and I'm using DirectSound for capture an...