I've tried some further debugging to see what mdf is actually doing. Instead of sending: tmp_out = (float)ref[i] - st->y[i+st->frame_size] to the output, I just sent st->y[i+st->frame_size] to see what was being subtracted from the microphone input. When I open this in Audacity, I see a very small signal at about -40dBm. The actual echo in my sample has a power closer to -20dBm. So, when the -40dBm estimated echo is removed from the -20dBm actual echo there is almost no perceived difference in the echo power. I'm sure that there are others on the list that have had good success with the echo cancellation module. Could anyone point me to reference test files that are known to work well in testecho. I'd like to figure out if there is some characteristic of my echo that makes it incompatible with this echo cancellation algorithm, or whether there is just some configuration problem in my implementation. Thanks for your time; advice is greatly appreciated. -Jason ---> I have incorporated the speex echo cancellation into > my softphone project, but wasn't getting great > results. I decided to simplify the problem, by > recording speaker and mic files and running > testecho. > I've been pretty happy with the preprocess module > and > I wanted to focus on the mdf, so I commented out the > call to preprocess in testecho. > When I run testecho my output file looks almost > identicle to my mic file. I don't see any reduction > in the power level of the echo. I've looked through > some of the previous posts to this group and have > tried the obvious, such as increasing my filter > length > and reversing the order of the files passed into the > application. > Looking at the files in Audacity, the echo lags by > about 180ms. I have experimented with filter > lengths > up to 2 seconds. > I'm open to suggestions.
I've recently made changes to the AEC. Please try the code in SVN and see if it works better. Jean-Marc Le jeudi 03 novembre 2005 ? 22:36 -0800, Jason Harper a ?crit :> I've tried some further debugging to see what mdf is > actually doing. Instead of sending: > tmp_out = (float)ref[i] - st->y[i+st->frame_size] > to the output, I just sent > st->y[i+st->frame_size] > to see what was being subtracted from the microphone > input. When I open this in Audacity, I see a very > small signal at about -40dBm. The actual echo in my > sample has a power closer to -20dBm. So, when the > -40dBm estimated echo is removed from the -20dBm > actual echo there is almost no perceived difference in > the echo power. > I'm sure that there are others on the list that have > had good success with the echo cancellation module. > Could anyone point me to reference test files that are > known to work well in testecho. > I'd like to figure out if there is some characteristic > of my echo that makes it incompatible with this echo > cancellation algorithm, or whether there is just some > configuration problem in my implementation. > Thanks for your time; advice is greatly appreciated. > > -Jason > > --- > > I have incorporated the speex echo cancellation into > > my softphone project, but wasn't getting great > > results. I decided to simplify the problem, by > > recording speaker and mic files and running > > testecho. > > I've been pretty happy with the preprocess module > > and > > I wanted to focus on the mdf, so I commented out the > > call to preprocess in testecho. > > When I run testecho my output file looks almost > > identicle to my mic file. I don't see any reduction > > in the power level of the echo. I've looked through > > some of the previous posts to this group and have > > tried the obvious, such as increasing my filter > > length > > and reversing the order of the files passed into the > > application. > > Looking at the files in Audacity, the echo lags by > > about 180ms. I have experimented with filter > > lengths > > up to 2 seconds. > > I'm open to suggestions. > > _______________________________________________ > Speex-dev mailing list > Speex-dev@xiph.org > http://lists.xiph.org/mailman/listinfo/speex-dev >
Thanks for alerting me to the new changes. I just tried the latest code from SVN, but unfortunately I still have just about the same results. The estimated echo that gets subtracted from the actual echo is such a small signal that it doesn't really result in any noticeable echo attenuation. I currently have my filter size set to 2 seconds even though the echo in my microphone file is only about 180ms delayed from the signal in my speaker file. I also double checked that the endianess of my is correct, and that I am providing the files to testecho in the correct order. Do you think that there could be some characteristics to my echo that make it not work with the mdf algorithm? How much echo attenuation should I expect from the mdf algorithm before the preprocess? Are there any test speaker and mic files that I could run against testecho to see how it handles other acoustic echos? -Jason --- Jean-Marc Valin <Jean-Marc.Valin@USherbrooke.ca> wrote:> I've recently made changes to the AEC. Please try > the code in SVN and > see if it works better. > > Jean-Marc > > Le jeudi 03 novembre 2005 ? 22:36 -0800, Jason > Harper a ?crit : > > I've tried some further debugging to see what mdf > is > > actually doing. Instead of sending: > > tmp_out = (float)ref[i] - st->y[i+st->frame_size] > > to the output, I just sent > > st->y[i+st->frame_size] > > to see what was being subtracted from the > microphone > > input. When I open this in Audacity, I see a very > > small signal at about -40dBm. The actual echo in > my > > sample has a power closer to -20dBm. So, when the > > -40dBm estimated echo is removed from the -20dBm > > actual echo there is almost no perceived > difference in > > the echo power. > > I'm sure that there are others on the list that > have > > had good success with the echo cancellation > module. > > Could anyone point me to reference test files that > are > > known to work well in testecho. > > I'd like to figure out if there is some > characteristic > > of my echo that makes it incompatible with this > echo > > cancellation algorithm, or whether there is just > some > > configuration problem in my implementation. > > Thanks for your time; advice is greatly > appreciated. > > > > -Jason > > > > --- > > > I have incorporated the speex echo cancellation > into > > > my softphone project, but wasn't getting great > > > results. I decided to simplify the problem, by > > > recording speaker and mic files and running > > > testecho. > > > I've been pretty happy with the preprocess > module > > > and > > > I wanted to focus on the mdf, so I commented out > the > > > call to preprocess in testecho. > > > When I run testecho my output file looks almost > > > identicle to my mic file. I don't see any > reduction > > > in the power level of the echo. I've looked > through > > > some of the previous posts to this group and > have > > > tried the obvious, such as increasing my filter > > > length > > > and reversing the order of the files passed into > the > > > application. > > > Looking at the files in Audacity, the echo lags > by > > > about 180ms. I have experimented with filter > > > lengths > > > up to 2 seconds. > > > I'm open to suggestions. > > > > _______________________________________________ > > Speex-dev mailing list > > Speex-dev@xiph.org > > http://lists.xiph.org/mailman/listinfo/speex-dev > > >