[Desktop-packages] [Bug 1159760] Re: av_rescale_q() returns wrong value on Precise amd64
thanks for clarifying the issue
** Changed in: libav (Ubuntu)
Status: New = Invalid
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https://bugs.launchpad.net/bugs/1159760
Title:
av_rescale_q() returns wrong value on Precise amd64
Status in “libav” package in Ubuntu:
Invalid
Bug description:
I found a bug with the function av_rescale_q() in the latest versions
on Precise LTS Lucid LTS on amd64 processor.
Below is my test code (to be linked against libavutilXX):
uint64_t av_rescale_q_test(uint64_t a, AVRational b, AVRational c)
{
uint64_t num = b.num * c.den;
uint64_t den = b.den * c.num;
return ( a * num + (den1)) / den;
}
void test()
{
uint64_t out, out2, pts=30305290;
AVRational base = { 1, 14112000};
AVRational bq = { 1, 10};
out = av_rescale_q(pts, base, bq);
out2 = av_rescale_q_test(pts, base, bq);
printf(pts=0x%lX, out=0x%lX, out2=0x%lX\n, pts, out, out2);
}
And the output is:
pts=0x1CE6C0A, out=0x8036, out2=0x8036
Obviously av_rescale_q() gives wrong answer.
The interesting thing is: if I pull the source code of av_rescale_q() and all
the invoked functions together from libav into my test code, the result becomes:
pts=0x1CE6C0A, out=0x8036, out2=0x8036
Looks like the libav sourcecode itself is OK, but the built library is
buggy. I have no idea how to further debug this problem. Somebody
please look into this bug. I believe it could be reappeared on all
amd64 distros including Lucid/Precie/Quantal.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/libav/+bug/1159760/+subscriptions
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[Desktop-packages] [Bug 1159760] Re: av_rescale_q() returns wrong value on Precise amd64
Sorry, it's due to the makefile and not a problem of libav.
If I compile using one invocation of gcc, like below, the return value is wrong.
gcc avutil-test.c -lavutil -o avutil-test
However, if I compile it in the following way, the return value is correct.
gcc -c avutil-test.c -o avutil-test.o
gcc avutil-test.o -lavutil -o avutil-test
This looks wierd.
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You received this bug notification because you are a member of Desktop
Packages, which is subscribed to libav in Ubuntu.
https://bugs.launchpad.net/bugs/1159760
Title:
av_rescale_q() returns wrong value on Precise amd64
Status in “libav” package in Ubuntu:
New
Bug description:
I found a bug with the function av_rescale_q() in the latest versions
on Precise LTS Lucid LTS on amd64 processor.
Below is my test code (to be linked against libavutilXX):
uint64_t av_rescale_q_test(uint64_t a, AVRational b, AVRational c)
{
uint64_t num = b.num * c.den;
uint64_t den = b.den * c.num;
return ( a * num + (den1)) / den;
}
void test()
{
uint64_t out, out2, pts=30305290;
AVRational base = { 1, 14112000};
AVRational bq = { 1, 10};
out = av_rescale_q(pts, base, bq);
out2 = av_rescale_q_test(pts, base, bq);
printf(pts=0x%lX, out=0x%lX, out2=0x%lX\n, pts, out, out2);
}
And the output is:
pts=0x1CE6C0A, out=0x8036, out2=0x8036
Obviously av_rescale_q() gives wrong answer.
The interesting thing is: if I pull the source code of av_rescale_q() and all
the invoked functions together from libav into my test code, the result becomes:
pts=0x1CE6C0A, out=0x8036, out2=0x8036
Looks like the libav sourcecode itself is OK, but the built library is
buggy. I have no idea how to further debug this problem. Somebody
please look into this bug. I believe it could be reappeared on all
amd64 distros including Lucid/Precie/Quantal.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/libav/+bug/1159760/+subscriptions
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[Desktop-packages] [Bug 1159760] Re: av_rescale_q() returns wrong value on Precise amd64
The way I found this bug is that when I was using gstreamer0.10-ffmpeg on
Ubuntu Precise amd64 to demux MP3 files, if you enable the plugin logs by
setting ffmepg:5, you will see the PTS in the log changed from a few seconds
to a very large value in a sudden.
Then I try to recompile the gstreamer0.10-ffmpeg and found that once the PTS
reaches 30305290, the return value of av_rescale_q() in
gst_ffmpeg_time_ff_to_gst() will go wrong by adding the 0x prefix to
the normal value. For example, when you expect the return value to be
0x8036, but it gives 0x8036.
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You received this bug notification because you are a member of Desktop
Packages, which is subscribed to libav in Ubuntu.
https://bugs.launchpad.net/bugs/1159760
Title:
av_rescale_q() returns wrong value on Precise amd64
Status in “libav” package in Ubuntu:
New
Bug description:
I found a bug with the function av_rescale_q() in the latest versions
on Precise LTS Lucid LTS on amd64 processor.
Below is my test code (to be linked against libavutilXX):
uint64_t av_rescale_q_test(uint64_t a, AVRational b, AVRational c)
{
uint64_t num = b.num * c.den;
uint64_t den = b.den * c.num;
return ( a * num + (den1)) / den;
}
void test()
{
uint64_t out, out2, pts=30305290;
AVRational base = { 1, 14112000};
AVRational bq = { 1, 10};
out = av_rescale_q(pts, base, bq);
out2 = av_rescale_q_test(pts, base, bq);
printf(pts=0x%lX, out=0x%lX, out2=0x%lX\n, pts, out, out2);
}
And the output is:
pts=0x1CE6C0A, out=0x8036, out2=0x8036
Obviously av_rescale_q() gives wrong answer.
The interesting thing is: if I pull the source code of av_rescale_q() and all
the invoked functions together from libav into my test code, the result becomes:
pts=0x1CE6C0A, out=0x8036, out2=0x8036
Looks like the libav sourcecode itself is OK, but the built library is
buggy. I have no idea how to further debug this problem. Somebody
please look into this bug. I believe it could be reappeared on all
amd64 distros including Lucid/Precie/Quantal.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/libav/+bug/1159760/+subscriptions
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Post to : desktop-packages@lists.launchpad.net
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