Attempt to detect Exynos 4 to apply the bitstream fixup code

decoder-errata.txt

@@ -1,7 +1,7 @@
 This file serves to document some of the decoder errata when using MediaCodec hardware decoders on certain devices.
 
-1. num_ref_frames is set to 16 by NVENC which causes decoders to allocate 16+ buffers. This can cause an error on some devices.
-	- Affected decoders: TI OMAP4, Exynos 4
+1. num_ref_frames is set to 16 by NVENC which causes decoders to allocate 16+ buffers. This can cause an error or lag on some devices.
+	- Affected decoders: TI OMAP4, Allwinner A20
 	
 2. Some decoders have a huge per-frame latency with the unmodified SPS sent from NVENC. Setting max_dec_frame_buffering fixes this latency issue.
 	- Affected decoders: NVIDIA Tegra 3 and 4
@@ -10,7 +10,7 @@ This file serves to document some of the decoder errata when using MediaCodec ha
 	- Affected decoders: TI OMAP4
 
 4. Some decoders require num_ref_frames=1 and max_dec_frame_buffering=1 to avoid crashing on SPS or first I-frame
-	- Affected decoders: Qualcomm in GS3 on 4.3+
+	- Affected decoders: Qualcomm in GS3 on 4.3+, Exynos 4 at 1080p only
 
 5. Some decoders will hang if max_dec_frame_buffering is not present
 	- Affected decoders: MediaTek decoder in Fire HD 7 (2014)

src/com/limelight/binding/video/MediaCodecDecoderRenderer.java

@@ -22,12 +22,13 @@ import android.media.MediaCodec.CodecException;
 import android.os.Build;
 import android.view.SurfaceHolder;
 
+@SuppressWarnings("unused")
 public class MediaCodecDecoderRenderer implements VideoDecoderRenderer {
 
 	private ByteBuffer[] videoDecoderInputBuffers;
 	private MediaCodec videoDecoder;
 	private Thread rendererThread;
-	private boolean needsSpsBitstreamFixup;
+	private boolean needsSpsBitstreamFixup, isExynos4;
 	private VideoDepacketizer depacketizer;
 	private boolean adaptivePlayback;
 	private int initialWidth, initialHeight;
@@ -65,6 +66,10 @@ public class MediaCodecDecoderRenderer implements VideoDecoderRenderer {
 		if (needsSpsBitstreamFixup) {
 			LimeLog.info("Decoder "+decoderName+" needs SPS bitstream restrictions fixup");
 		}
+		isExynos4 = MediaCodecHelper.isExynos4Device();
+		if (isExynos4) {
+			LimeLog.info("Decoder "+decoderName+" is on Exynos 4");
+		}
 	}
 	
 	@TargetApi(Build.VERSION_CODES.LOLLIPOP)
@@ -406,7 +411,7 @@ public class MediaCodecDecoderRenderer implements VideoDecoderRenderer {
 				LimeLog.info("Patching num_ref_frames in SPS");
 				sps.num_ref_frames = 1;
 				
-				if (needsSpsBitstreamFixup) {
+				if (needsSpsBitstreamFixup || isExynos4) {
 					// The SPS that comes in the current H264 bytestream doesn't set bitstream_restriction_flag
 					// or max_dec_frame_buffering which increases decoding latency on Tegra.
 					LimeLog.info("Adding bitstream restrictions");
@@ -512,6 +517,15 @@ public class MediaCodecDecoderRenderer implements VideoDecoderRenderer {
 				str += "Buffer codec flags: "+currentCodecFlags+"\n";
 			}
 			
+			str += "Is Exynos 4: "+renderer.isExynos4+"\n";
+			
+			str += "/proc/cpuinfo:\n";
+			try {
+				str += MediaCodecHelper.readCpuinfo();
+			} catch (Exception e) {
+				str += e.getMessage();
+			}
+			
 			str += "Full decoder dump:\n";
 			try {
 				str += MediaCodecHelper.dumpDecoders();

src/com/limelight/binding/video/MediaCodecHelper.java

@@ -1,7 +1,11 @@
 package com.limelight.binding.video;
 
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Locale;
 
 import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
@@ -233,4 +237,63 @@ public class MediaCodecHelper {
 		
 		return null;
 	}
+	
+	public static String readCpuinfo() throws Exception {
+		StringBuilder cpuInfo = new StringBuilder();
+		BufferedReader br = new BufferedReader(new FileReader(new File("/proc/cpuinfo")));
+		try {
+			for (;;) {
+				int ch = br.read();
+				if (ch == -1)
+					break;
+				cpuInfo.append((char)ch);
+			}
+			
+			return cpuInfo.toString();
+		} finally {
+			br.close();
+		}
+	}
+	
+	private static boolean stringContainsIgnoreCase(String string, String substring) {
+		return string.toLowerCase(Locale.ENGLISH).contains(substring.toLowerCase(Locale.ENGLISH));
+	}
+	
+	public static boolean isExynos4Device() {
+		try {
+			// Try reading CPU info too look for 
+			String cpuInfo = readCpuinfo();
+			
+			// SMDK4xxx is Exynos 4 
+			if (stringContainsIgnoreCase(cpuInfo, "SMDK4")) {
+				LimeLog.info("Found SMDK4 in /proc/cpuinfo");
+				return true;
+			}
+			
+			// If we see "Exynos 4" also we'll count it
+			if (stringContainsIgnoreCase(cpuInfo, "Exynos 4")) {
+				LimeLog.info("Found Exynos 4 in /proc/cpuinfo");
+				return true;
+			}
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+		
+		try {
+			File systemDir = new File("/sys/devices/system");
+			File[] files = systemDir.listFiles();
+			if (files != null) {
+				for (File f : files) {
+					if (stringContainsIgnoreCase(f.getName(), "exynos4")) {
+						LimeLog.info("Found exynos4 in /sys/devices/system");
+						return true;
+					}
+				}
+			}
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+		
+		return false;
+	}
 }