| page.title=OEM Dependencies for Media Resource Manager |
| @jd:body |
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| <div id="qv-wrapper"> |
| <div id="qv"> |
| <h2>In this document</h2> |
| <ol id="auto-toc"> |
| </ol> |
| </div> |
| </div> |
| |
| <p>This document is intended to help original equipment manufacturers (OEMs) |
| properly implement support for Android media resource manager and related APIs.</p> |
| |
| <h2 id=1_max_concurrent_codec_instances>1. Max concurrent codec instances</h2> |
| |
| <p>The <code>CodecCapabilities.getMaxSupportedInstances</code> interface |
| returns the maximum number of supported concurrent codec instances.</p> |
| |
| <p>The CTS test |
| <code>testGetMaxSupportedInstances(android.media.cts.MediaCodecCapabilitiesTest)</code> |
| is used to enforce the proper maximum is set in |
| <code>/etc/media_codecs.xml</code>.</p> |
| |
| <p>Here is an example:</p> |
| |
| <pre> |
| ... |
| <MediaCodecs> |
| ... |
| <Encoders> |
| <MediaCodec name="OMX.<em><vendor></em>.video.encoder.avc" type="video/avc" > |
| ... |
| <Limit name="concurrent-instances" max="13" /> |
| </MediaCodec> |
| ... |
| </Encoders> |
| ... |
| </MediaCodecs> |
| </pre> |
| |
| <p>OEMs can use this test to generate the concurrent limits that pass the test. |
| To do this:</p> |
| |
| <ol> |
| <li>Run the test first using cts-tradefed. |
| <li>Evaluate the resulting failure message. Here is an example: |
| |
| <pre> |
| There was 1 failure: |
| 1) testGetMaxSupportedInstances(android.media.cts.MediaCodecCapabilitiesTest) |
| junit.framework.AssertionFailedError: In order to pass the test, please publish |
| following codecs' concurrent instances limit in /etc/media_codecs.xml: |
| <MediaCodec name="OMX.<em><vendor></em>.video.encoder.mpeg4" type="video/mp4v-es" > |
| <Limit name="concurrent-instances" max="13" /> |
| </MediaCodec> |
| <MediaCodec name="OMX.<em><vendor></em>.video.encoder.h263" type="video/3gpp" > |
| <Limit name="concurrent-instances" max="13" /> |
| </MediaCodec> |
| <MediaCodec name="OMX.<em><vendor></em>.video.encoder.avc" type="video/avc" > |
| <Limit name="concurrent-instances" max="13" /> |
| </MediaCodec> |
| <MediaCodec name="OMX.<em><vendor></em>.video.encoder.vp8" type="video/x-vnd.on2.vp8" > |
| <Limit name="concurrent-instances" max="13" /> |
| </MediaCodec> |
| <MediaCodec name="OMX.<em><vendor></em>.video.decoder.avc" type="video/avc" > |
| <Limit name="concurrent-instances" max="13" /> |
| </MediaCodec> |
| <MediaCodec name="OMX.<em><vendor></em>.video.decoder.avc.secure" type="video/avc" > |
| <Limit name="concurrent-instances" max="4" /> |
| </MediaCodec> |
| <MediaCodec name="OMX.<em><vendor></em>.video.decoder.mpeg4" type="video/mp4v-es" > |
| <Limit name="concurrent-instances" max="12" /> |
| </MediaCodec> |
| <MediaCodec name="OMX.<em><vendor></em>.video.decoder.h263" type="video/3gpp" > |
| <Limit name="concurrent-instances" max="12" /> |
| </MediaCodec> |
| <MediaCodec name="OMX.<em><vendor></em>.video.decoder.vp8" type="video/x-vnd.on2.vp8" > |
| <Limit name="concurrent-instances" max="12" /> |
| </MediaCodec> |
| </pre> |
| |
| <li>Add the <code>concurrent-instances</code> lines suggested in the test |
| failure message to the <code>/etc/media_codecs.xml</code> file. |
| |
| <li>Re-run the test to verify its success. |
| </ol> |
| |
| <h2 id=2_achievable_frame_rates_for_video_codecs>2. Achievable frame rates for video codecs</h2> |
| <p>The <code>VideoCapabilities.getAchievableFrameRatesFor</code> interface |
| returns the range of achievable video frame rates for a video size. This |
| information must be provided by the OEM for each device via an XML file placed at |
| <code>/etc/media_codecs_performance.xml</code>. These settings are tested by |
| the <code>com.android.cts.videoperf.VideoEncoderDecoderTest</code> and |
| <code>android.media.cts.VideoDecoderPerfTest</code> CTS tests.</p> |
| |
| <p>OEMs can use the CTS tests to generate the XML files that pass the tests. To do this:</p> |
| <ol> |
| <li>Run the tests first using cts-tradefed. Given the |
| variability of Android performance, it is recommended the tests are run |
| multiple times to get more accurate minimum and maximum values. |
| <li>Use the provided <a |
| href="https://android.googlesource.com/platform/cts/+/marshmallow-cts-dev/tools/cts-media/get_achievable_rates.py">get_achievable_rates.py</a> |
| script to generate the XML file. |
| <li>Place the XML file at: <code>/etc/media_codecs_performance.xml</code><br> |
| This is usually done by placing the XML file in the device project |
| (device/<em><vendor></em>/<em><product></em>) and adding a |
| <code>PRODUCT_COPY_FILES</code> line to <code>device.mk</code> like so: |
| <pre> |
| PRODUCT_COPY_FILES += \ |
| ... |
| device/moto/shamu/media_codecs.xml:system/etc/media_codecs.xml \ |
| + device/moto/shamu/media_codecs_performance.xml:system/etc/media_codecs_performance.xml |
| </pre> |
| <li>Re-run the performance tests to verify their success. |
| </ol> |
| |
| <h2 id=3_co-exist_of_secure_codec_and_non-secure_codec>3. Co-exist of secure codec and non-secure codec</h2> |
| |
| <ul> |
| <li>supports-secure-with-non-secure-codec — |
| If the instance of secure codec and the instance of non-secure codec can’t |
| co-exist at the same time, that should be indicated as global setting in the |
| <code>media_codecs.xml</code> file. |
| <pre> |
| <MediaCodecs> |
| <Settings> |
| <Setting name="supports-secure-with-non-secure-codec" value="false" /> |
| </Settings> |
| <Encoders> |
| … |
| </pre> |
| <li>supports-multiple-secure-codecs — |
| If co-exist of multiple secure codec instances is not supported, that should be |
| indicated as a global setting in the <code>media_codecs.xml</code> file. |
| <pre> |
| <MediaCodecs> |
| <Settings> |
| <Setting name="supports-multiple-secure-codecs" value="false" /> |
| </Settings> |
| <Encoders> |
| … |
| </pre> |
| <li>Note that the both settings are true by default, meaning if they are supported, |
| there’s no need to add the setting line to the <code>media_codecs.xml</code>. |
| <li>The <code>ResourceManagerTest</code> CTS tests may fail if these two settings were not set |
| properly. |
| </ul> |
