diff options
| -rw-r--r-- | media/java/android/media/MediaCodecInfo.java | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/media/java/android/media/MediaCodecInfo.java b/media/java/android/media/MediaCodecInfo.java index 45d0cc025a16..07d1f7542b26 100644 --- a/media/java/android/media/MediaCodecInfo.java +++ b/media/java/android/media/MediaCodecInfo.java @@ -1372,16 +1372,33 @@ public final class MediaCodecInfo { * May return {@code null}, if the codec did not publish any measurement * data. * <p> - * This is a performance estimate provided by the device manufacturer - * based on full-speed decoding and encoding measurements in various configurations + * This is a performance estimate provided by the device manufacturer based on statistical + * sampling of full-speed decoding and encoding measurements in various configurations * of common video sizes supported by the codec. As such it should only be used to * compare individual codecs on the device. The value is not suitable for comparing * different devices or even different android releases for the same device. * <p> - * The returned range corresponds to the fastest frame rates achieved in the tested - * configurations. It is interpolated from the nearest frame size(s) tested. Codec - * performance is severely impacted by other activity on the device, and can vary - * significantly. + * <em>On {@link android.os.Build.VERSION_CODES#M} release</em> the returned range + * corresponds to the fastest frame rates achieved in the tested configurations. As + * such, it should not be used to gauge guaranteed or even average codec performance + * on the device. + * <p> + * <em>On {@link android.os.Build.VERSION_CODES#N} release</em> the returned range + * corresponds closer to sustained performance <em>in tested configurations</em>. + * One can expect to achieve sustained performance higher than the lower limit more than + * 50% of the time, and higher than half of the lower limit at least 90% of the time + * <em>in tested configurations</em>. + * Conversely, one can expect performance lower than twice the upper limit at least + * 90% of the time. + * <p class=note> + * Tested configurations use a single active codec. For use cases where multiple + * codecs are active, applications can expect lower and in most cases significantly lower + * performance. + * <p class=note> + * The returned range value is interpolated from the nearest frame size(s) tested. + * Codec performance is severely impacted by other activity on the device as well + * as environmental factors (such as battery level, temperature or power source), and can + * vary significantly even in a steady environment. * <p class=note> * Use this method in cases where only codec performance matters, e.g. to evaluate if * a codec has any chance of meeting a performance target. Codecs are listed |