Android – Matrix scale video on TextureView Android

androidexoplayerscalevideo

I'm trying to play video with ExoPlaye on TextureView. In order to scale and crop video to fit view I use matrix. My custom view extends `TextureView' Here is my code:

@Override
public void onVideoSizeChanged(int width, int height, float pixelWidthHeightRatio) {
    updateTextureViewSize(width, height);
    Log.v("EXO", "onVideoSizeChanged() " +  width + "x" + height);
}

private void updateTextureViewSize(float videoWidth, float videoHeight) {
    float viewWidth = getWidth();
    float viewHeight = getHeight();

    float scaleX = 1.0f;
    float scaleY = 1.0f;

    float viewRatio = viewWidth / viewHeight;
    float videoRatio = videoWidth / videoHeight;
    if (viewRatio > videoRatio) {
        // video is higher than view
        scaleY = videoHeight / videoWidth;
    } else {
        //video is wider than view
        scaleX = videoWidth / videoHeight;
    }

    Matrix matrix = new Matrix();
    matrix.setScale(scaleX, scaleY, viewWidth / 2, viewHeight / 2);


    setTransform(matrix);
}

I had a rectangular views and it worked perfectly. But now views have 2 states: expanded (the old ones that are still rectangular) and collapsed (have smaller height.

So now video is stretched vertically in those collapsed views.

For instance I have view 1080x480 and video 360x640 but it looks like video is scaled and cropped to 1080x1080 and than stretched to 1080x480.

What am I doing wrong here ?

UPD: Here are screenshots:

Best Answer

I fixed this issue next by multiplying or dividing scale factors by viewRatio (width / height):

    if (viewRatio > videoRatio) {
        // video is higher than view
        scaleY = videoHeight / videoWidth * viewRatio;
    } else {
        //video is wider than view
        scaleX = videoWidth / videoHeight / viewRatio;
    }

But I did not get why it works like this. According to my calculations if I have, for instance, view 1080x480 and video 360x640 video should be scaled to have width x' = 1080 and height proportional. So height should be y' = 640*1080/360 (videoHeight * viewHeight / videoWidth) and x' = 1080

According to this image:

sx * 360 = 1080 => sx = 1080 / 360

sy * 640 = 640*1080/360 => sy = 1080 / 360

Looks like it makes sense. If we need save proportions width and height should be multiplied by the same factor. But it does not work this way. Where is a mistake ? Is there any good doc on this ?

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Here's what I created to hold the images that my app is currently displaying. Please note that the "Log" object in use here is my custom wrapper around the final Log class inside Android.

package com.wilson.android.library;

/*
 Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
*/
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public class DrawableManager {
    private final Map<String, Drawable> drawableMap;

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    }

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                        + drawable.getIntrinsicHeight() + "," + drawable.getIntrinsicWidth() + ", "
                        + drawable.getMinimumHeight() + "," + drawable.getMinimumWidth());
            } else {
              Log.w(this.getClass().getSimpleName(), "could not get thumbnail");
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        } catch (IOException e) {
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            return null;
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    public void fetchDrawableOnThread(final String urlString, final ImageView imageView) {
        if (drawableMap.containsKey(urlString)) {
            imageView.setImageDrawable(drawableMap.get(urlString));
        }

        final Handler handler = new Handler() {
            @Override
            public void handleMessage(Message message) {
                imageView.setImageDrawable((Drawable) message.obj);
            }
        };

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            @Override
            public void run() {
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        };
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        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpGet request = new HttpGet(urlString);
        HttpResponse response = httpClient.execute(request);
        return response.getEntity().getContent();
    }
}

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