Hello,
I am seeing a very annoying behavior on Motorola Droid when trying to
do a simple camera preview at QCIF resolution. And I was wondering if
someone experienced something similar. Is there a workaround? Am I
doing something wrong?
Let me explain the situation.
Firstly, right after boot-up, using native camera application there is
nothing out of ordinary, I see preview each time and it is all
perfectly well for as long as needed as many times as I want.
The "interesting" behavior starts when I use the slightly modified API
Demos (full app available in Android SDK, modified file is attached).
My goal is to preview (and later capture) video at QCIF (176 x 144)
resolution.
Using CameraPreview module in API Demos application I can start
preview and capture normally only the first time – picture is clear,
focused, normal colors, etc. Preview and all is nice. The second time
I do preview I see a very over-exposed picture, I need to turn it away
from any light source to see anything, otherwise it is all white. And
even in the shadow, everything is grainy, as if picture is taken with
too sensitive settings (high ISO) with too long exposure. The third
time, it is the opposite – the preview and capture is way too dark. I
need to point the camera directly into the light source to see even a
faintest picture. Pointing out of the window does not help, it has to
be straight into the lamp or sun. The effect is like taking pictures
with much too low ISO setting – it is way too underexposed.
The overexposed and underexposed sessions interchange, but it is not
clear-cut which one appears first. So far the prevailing pattern is
that overexposed one starts first. Now surprise comes when I try using
native camera application. The pattern continues! It is as if hardware
or or software (camera process) got "tainted" with the QCIF. This
continues until I reboot the device.
Another interesting point is that if I allow device to "rest",
symptoms are much less pronounced after 10 minutes, then in 15 minutes
they become barely visible. However, it all comes back after the first
time I capture in QCIF. Nothing like this is visible when resolution
is higher, say, CIF, VGA or similar. The problem is that, for my
purposes I need it to be QCIF.
This does look like a problem in HW, drivers, or somewhere around OS.
Any ideas, workarounds, tricks?
If it is not too much to ask, can somebody try the code modifications
below to try on your device? I am curious which devices are working
properly and which are not. Shall we have a vote?
=== Device Information ===
Firmware version: 2.1-update-1
Baseband version: C_01.3E.03P
Kernel version: 2.6.29-omap1-g7fa8788 android-bu...@apa26 #1
Build number: ESE81
=== To reproduce ===
Open CameraPreview.java from <SDK root>/samples/android-7/ApiDemos/src/
com/example/android/apis/graphics, and add the following method:
@Override
protected void onMeasure(int w, int h) {
super.onMeasure(w, h);
setMeasuredDimension(176, 144);
}
Also in the surfaceChanged method, add the following line:
parameters.setPreviewFrameRate(15);
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