README.dev.md

encapp development

This page provides instructions on how to build and develop encapp, including using the tool without the encapp.py script.

For a description on how to use the tool, check README.md.

1. Prerequisites

In order to do encapp development, you need:

• android sdk setup and environment variables set
• android ndk

Please note that since JDK 16 gradle versions < 7 are broken. This means that a JDK version >= 16 must be used for building.

2. Operation

2.1. set up the android SDK and NDK in the local.properties file.

Create a local.properties file with valid entries for the ndk.dir and sdk.dir variables.

$ cat local.properties
ndk.dir: /opt/android_ndk/android-ndk-r19/
sdk.dir: /opt/android_sdk/

Note that this file should not be added to the repo.

2.2. build the encapp app

$ ./gradlew clean
$ ./gradlew build
...
BUILD SUCCESSFUL in 6s
61 actionable tasks: 5 executed, 56 up-to-date

2.3. run the setup.sh script to install encapp in your android device.

$ ./setup.sh
...
Installing APK 'com.facebook.encapp-v1.0-debug.apk' on 'Pixel - 10' for app:debug
Installed on 4 devices.

BUILD SUCCESSFUL in 14s
31 actionable tasks: 3 executed, 28 up-to-date

2.4. run a quick encoding experiment with the app

Install the app.

$ adb install ./app/build/outputs/apk/debug/com.facebook.encapp-v1.0-debug.apk
$ adb shell cmd package list package |grep encapp
package:com.facebook.encapp

Run the list_codecs function.

Note that, for the very first time you run the instrumentation codecs, the device will ask you for permission to access to /sdcard/.

Figure 1 shows

$ adb shell am start -W -e list_codecs a -e ui_hold_sec 3 com.facebook.encapp/.MainActivity
Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.facebook.encapp/.MainActivity (has extras) }
Status: ok
LaunchState: COLD
Activity: com.facebook.alohaapps.launcher/com.facebook.aloha.app.home.touch.HomeActivity
TotalTime: 1479
WaitTime: 1482
Complete

$ adb shell cat /sdcard/codecs.txt
--- List of supported encoders  ---

        MediaCodec {
            name: OMX.qcom.video.encoder.avc
            type {
                mime_type: video/avc
                max_supported_instances: 24
                color {
                    format: 2141391878
                }
                color {
                    format: 2141391876
                }
                color {
                    format: 2141391872
                    name: COLOR_QCOM_FormatYUV420SemiPlanar
                }
                color {
                    format: 2141391881
                }
                color {
                    format: 2141391882
                }
                color {
                    format: 2141391880
                }
                color {
                    format: 2141391879
                }
                color {
                    format: 2130708361
                    name: COLOR_FormatSurface
                }
                color {
                    format: 2135033992
                    name: COLOR_FormatYUV420Flexible
                }
                color {
                    format: 21
                    name: COLOR_FormatYUV420SemiPlanar
                }
                profile {
                    profile: 65536
                    level: 65536
                }
                profile {
                    profile: 1
                    level: 65536
                }
                profile {
                    profile: 2
                    level: 65536
                }
                profile {
                    profile: 524288
                    level: 65536
                }
                profile {
                    profile: 8
                    level: 65536
                }
            }
        }

        MediaCodec {
            name: OMX.qcom.video.encoder.h263sw
            type {
...

3. Regression test

encapp_verify.py will run through the tests defined in 'tests/' folder and try to verify:

• bitrate
• key frames
• temporal layers
• long temporal references (Qualcomm ltr)

Just like encapp.py overrides for input and encoder are available. Run the test just like they are defined:

$ encapp_verify.py

Override the input, encoding resolution and codec:

$ encapp_verify.py -i /media/johan/data/media_encapp/<encoded>.mp4  -os 1920x1080 -c encoder.avc

This only works (for now) for encoded files and not raw files.

Override input and run specific test:

$ encapp_verify.py -i /tmp/KristenAndSara_1280x720_60.yuv -is 1280x720 -if 30 -os 1280x720 -of 30 -t <PATH>/encapp/tests/simple.qcif.json

For a raw input both input and output resolution and fps needs to be specified even if raw buffer will not allow scaling (which surface encoding does).