Compress Videos using FFMPEG and JNI

Question

I want to create an android application which can locate a video file (which is more than 300 mb) and compress it to lower size mp4 file.

i already tried to do it with this

This tutorial is a very effective since you 're compressing a small size video (below than 100 mb)

So i tried to implement it using JNI .

i managed to build ffmpeg using this

But currently what I want to do is to compress videos . I don't have very good knowledge on JNI. But i tried to understand it using following link

If some one can guide me the steps to compress video after open file it using JNI that whould really great , thanks

you say that the tutorial is very effective for small size video. So is there any problem when you follow the same for large videos? — Andro Selva, Dec 17 '13 at 11:16

dbro · Answer 1 · 2014-01-03T17:43:38.267

6

Assuming you've got the String path of the input file, we can accomplish your task fairly easily. I'll assume you have an understanding of the NDK basics: How to connect a native .c file to native methods in a corresponding .java file (Let me know if that's part of your question). Instead I'll focus on how to use FFmpeg within the context of Android / JNI.

High-Level Overview:

#include <jni.h>
#include <android/log.h>
#include <string.h>
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"

#define LOG_TAG "FFmpegWrapper"
#define LOGI(...)  __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
#define LOGE(...)  __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)


void Java_com_example_yourapp_yourJavaClass_compressFile(JNIEnv *env, jobject obj, jstring jInputPath, jstring jInputFormat, jstring jOutputPath, jstring JOutputFormat){
  // One-time FFmpeg initialization
  av_register_all();
  avformat_network_init();
  avcodec_register_all();

  const char* inputPath = (*env)->GetStringUTFChars(env, jInputPath, NULL);
  const char* outputPath = (*env)->GetStringUTFChars(env, jOutputPath, NULL);
  // format names are hints. See available options on your host machine via $ ffmpeg -formats
  const char* inputFormat = (*env)->GetStringUTFChars(env, jInputFormat, NULL);
  const char* outputFormat = (*env)->GetStringUTFChars(env, jOutputFormat, NULL);

  AVFormatContext *outputFormatContext = avFormatContextForOutputPath(outputPath, outputFormat);
  AVFormatContext *inputFormatContext = avFormatContextForInputPath(inputPath, inputFormat /* not necessary since file can be inspected */);

  copyAVFormatContext(&outputFormatContext, &inputFormatContext);
  // Modify outputFormatContext->codec parameters per your liking
  // See http://ffmpeg.org/doxygen/trunk/structAVCodecContext.html

  int result = openFileForWriting(outputFormatContext, outputPath);
  if(result < 0){
      LOGE("openFileForWriting error: %d", result);
  }

  writeFileHeader(outputFormatContext);

  // Copy input to output frame by frame
  AVPacket *inputPacket;
  inputPacket = av_malloc(sizeof(AVPacket));

  int continueRecording = 1;
  int avReadResult = 0;
  int writeFrameResult = 0;
  int frameCount = 0;
  while(continueRecording == 1){
      avReadResult = av_read_frame(inputFormatContext, inputPacket);
      frameCount++;
      if(avReadResult != 0){
        if (avReadResult != AVERROR_EOF) {
            LOGE("av_read_frame error: %s", stringForAVErrorNumber(avReadResult));
        }else{
            LOGI("End of input file");
        }
        continueRecording = 0;
      }

      AVStream *outStream = outputFormatContext->streams[inputPacket->stream_index];
      writeFrameResult = av_interleaved_write_frame(outputFormatContext, inputPacket);
      if(writeFrameResult < 0){
          LOGE("av_interleaved_write_frame error: %s", stringForAVErrorNumber(avReadResult));
      }
  }

  // Finalize the output file
  int writeTrailerResult = writeFileTrailer(outputFormatContext);
  if(writeTrailerResult < 0){
      LOGE("av_write_trailer error: %s", stringForAVErrorNumber(writeTrailerResult));
  }
  LOGI("Wrote trailer");
}

For the full content of all the auxillary functions (the ones in camelCase), see my full project on Github. Got questions? I'm happy to elaborate.

edited Jan 03 '14 at 17:43

answered Dec 21 '13 at 06:57

dbro

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i'll try it and let u know , can u send me ur mail address, – Mr.G Dec 23 '13 at 05:30
I have downloaded your sample application from GIT but it that seems it works for only android 4.4 – Mr.G Dec 23 '13 at 07:18
as u said i know "How to connect a native .c file to native methods in a corresponding .java file" i want to know the native c code to compress video, i tried to execute ut Github project but it seems that it works on android 4.4 – Mr.G Dec 23 '13 at 11:04
The GitHub project I linked is an experiment with [MediaCocec](http://developer.android.com/reference/android/media/MediaCodec.html) and FFmpeg, and that's where the Android 4.3 requirement comes from. The core files you want to include in your app are the `jni/` folder and `FFmpegWrapper.java`. You'll modify FFmpegWrapper.c and FFmpegWrapper.java to only expose the one function I included in my response. Also see my notes on [building FFmpeg for Android](https://github.com/OnlyInAmerica/FFmpeg-Android) when you need to configure the FFmpeg libraries for your needs. – dbro Dec 27 '13 at 01:50
i tried to excute program i recieve this error in my log-cat Caused by: java.lang.UnsatisfiedLinkError: Cannot load library: link_image[1936]: 138 could not load needed library 'libavformat-55.so' for 'libFFmpegWrapper.so' (load_library[1091]: Library 'libavformat-55.so' not found) But the libavcodec-55.so is available in the lib folder – Mr.G Dec 30 '13 at 05:19
Have you also copied [Android.mk](https://github.com/OnlyInAmerica/FFmpegTest/blob/365fdd214f5749400107924a91b23f1580244490/jni/Android.mk)? What happens when you run `ndk-build` in your terminal from the project's jni directory? – dbro Dec 30 '13 at 18:48
yeah . i copied Android.mk file and ndk-build runs and it will build app the .so files . So i think thr is an issue with linking files . Also i tried to run ur sample application . it gives same error. – Mr.G Dec 31 '13 at 06:36
Can you post the source to your application? – dbro Jan 03 '14 at 17:55
i have made a sample application to run ur native source . but it gives that error , which i mentioned above . i f u send me mail address i can send you the source code' – Mr.G Jan 06 '14 at 08:17
Put it up on Github so we can share the solution with everyone here. – dbro Jan 06 '14 at 20:54
sure. i'll add it to github. – Mr.G Jan 07 '14 at 05:25
@dbro How can I call this function with desired parameters ? I know how to call it.. but specifically doubt about passing params. – SachinGutte Feb 15 '14 at 08:07
I spend a lot of time and later could not get past the error undefined reference to 'avformat_new_stream' 'avformat_close_input' and some more functions. I could see these functions were defined in libavformat/utils.c but when I try to import, the compiler cannot find utils.c and I am still unable to compile the code. – JaydeepW Feb 20 '14 at 12:45
@dbro : Hello, " How to connect a native .c file to native methods in a corresponding .java file" is my issue, would you like to help me? I know `Java_com_example_yourapp_yourJavaClass_compressFile` means what. But I don't know how to define in Java class and MK file to load it, call this method ... – Huy Tower Mar 24 '14 at 02:20
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It just copies video not compresses the size. – Biraj Zalavadia May 06 '15 at 05:58
@BirajZalavadia to compress you modify AVFormatContext *outputFormatContext after it's initialized with `copyAVFormatContext`. See the comment in the code I embedded for a helpful link to the FFmpeg docs. – dbro May 06 '15 at 16:12
I think we need to know how to compress the video.Which method can do it? – wangqi060934 Jul 23 '15 at 10:48
in this method "inputformat" and "outputformat" which value passed from java class ? – axita.savani Oct 14 '19 at 04:55

Compress Videos using FFMPEG and JNI

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