Sur d’autres sites (11948)

• ffmpeg avcodec_decode_video2 is crashing the Android app

  6 février 2014, par Azhagiri

  HI i am using ffmpeg library in my android app. Using the library from
  https://github.com/churnlabs/android-ffmpeg-sample

  My application crashes when i am calling the avcodec_decode_video2() function. My code

      int decode_packet(int *got_frame, int cached){
  
      int ret = 0;
  
      int decoded = packet.size;
  
      if (packet.stream_index == videoStream) {
  
      /* decode video frame */
  
      ret = avcodec_decode_video2(pCodecCtx, pFrame, got_frame, &packet);
  
      if (ret < 0) {
  
      LOGE("Error decoding video frame");
  
      return ret;
  
      }
  
      if (*got_frame) {
  
           av_image_copy(video_dst_data, video_dst_linesize, (const uint8_t **)(pFrame->data), pFrame->linesize, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height);
  
          /* write to rawvideo file */
  
           LOGE("Frame Count [%d]",video_frame_count++);
  
      //  fwrite(video_dst_data[0], 1, video_dst_bufsize, videoOut);
  
      }
  
      return decoded;
  
      }
  
  }

  The app crashes at the line

  ret = avcodec_decode_video2(pCodecCtx, pFrame, got_frame, &packet);

  Help to get resolve the problem. I'll attach the ndk-stack output also

  ********** Crash dump: **********
  
  Build fingerprint: 'samsung/ja3gxx/ja3g:4.2.2/JDQ39/I9500XWUBMG5:user/release-keys'
  
  pid: 12494, tid: 12512, name: Thread-1088  >>> com.churnlabs.ffmpegsample <<<
  
  signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 00000020
  
  Stack frame #00  pc 00285804  /data/app-lib/com.churnlabs.ffmpegsample-1/libffmpegutils.so (avcodec_decode_video2+60)
  
  Stack frame #01  pc 00285854  /data/app-lib/com.churnlabs.ffmpegsample-1/libffmpegutils.so (avcodec_decode_video2+140)
  
  Crash dump is completed

  From this i can find the function which crashes but i can't find the reason for the crash and how to get out from that

• What video format will allow Android MediaPlayer.seekTo() to reliably provide frame-accurate scrubbing ?

  8 juillet 2015, par Tim Closs

  We have an iOS app that we are currently rebuilding for Android. The app relies on being able to scrub video with frame accuracy. We have 3D animations that are rendered out as single frames ; we build subsets of frames into lots of small (1-2 second) videos ; and the app provides the ability to scrub those videos and see each individual frame.

  The MP4 videos we initially created work fine on iOS. When we tried to get them working on Android (using the MediaPlayer class), we entered a world of pain ! What we need to do is find a video format that will play and allow frame-accurate scrubbing across all Android devices, using MediaPlayer.seekTo(). Initially we are targetting Android 3.0 and above, but we probably want to stretch back to 2.3.3 after our initial release. Here’s what I’ve discovered so far :

  (A) Android claims that H264 "baseline profile" should be supported everywhere : (URL). However, within that, there are dozens of other settings that may or may not be supported. Is there a more fine-grained list anywhere ? Currently we are converting to H264 within an MP4 container.

  (B) I haven’t yet seen an Android device that will accurately scrub H264 files without inserting keyframes ("intra frames"). iOS will happily take H264 files without keyframes and provide accurate scrubbing. It seems that, to allow accurate scrubbing, we need to insert a keyframe for every frame of the video (the relevant ffmpeg setting is "-g 1"). This significantly increases the file size.

  (C) However, inserting a keyframe for every frame results in a video that will not play at all on the Samsung Galaxy Note 3 (Snapdragon chipset I believe). Reducing the keyframes to every second frame or above seems to work (ffmpeg setting "-g 2").

  To summarise :
  MediaPlayer.seekTo() seems very dependent on the video format, and varies across devices. Is this the intention ? Is there a base level of behaviour that seekTo() is supposed to provide, regardless of format ?

  What video format that will allow frame-accurate scrubbing (using MediaPlayer.seekTo()) across all Android devices (at least for 3.0 and above ?)

• ffmpeg commands not working in micromax android

  10 février 2014, par pavan

  I am able to execute ffmpeg commands on android devices like Samsung,LG and Sony but in Micromax it's not working. I have built ffmpeg library for arm processor. I could not collect the log because I am not able to connect the device. I have following questions on this,
  1) Why it's not working on Micromax ?
  2) I do not want to show my app on other device apart from ARM based android device, is it possible to control ?

  The below configuration I have used while building ffmpeg,

   !/bin/bash

  cd ffmpeg

  export TMPDIR=tmp
  mkdir -p $TMPDIR

  Android NDK Location

  NDK=/Users/sunitha/Downloads/android-ndk-r9c

  ANDROID_API=android-9
  SYSROOT=$NDK/platforms/$ANDROID_API/arch-arm
  PREBUILT=$NDK/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-x86
  CROSS_PREFIX=$PREBUILT/bin/arm-linux-androideabi-
  ARM_INCLUDE=$SYSROOT/usr/include
  ARM_LIB=$SYSROOT/usr/lib
  PREFIX=../build
  OPTIMIZE_CFLAGS=" -marm -march=armv6 "
  ADDITIONAL_CONFIGURE_FLAG=

  Location of lame's static installation

  MP3LAME=../libmp3lame
  X264=../libx264

  ./configure \
  —arch=arm \
  —target-os=linux \
  —enable-cross-compile \
  —cross-prefix=$CROSS_PREFIX \
  —prefix=$PREFIX \
  —sysroot=$SYSROOT \
  —extra-cflags=" -I$ARM_INCLUDE -I$MP3LAME/include -I$X264/include -DANDROID $OPTIMIZE_CFLAGS" \
  —extra-ldflags=" -L$ARM_LIB -L$MP3LAME/lib -L$X264/lib" \
  —disable-debug \
  —enable-libmp3lame \
  —enable-libx264 \
  —disable-ffplay \
  —disable-ffprobe \
  —disable-ffserver \
  —enable-avfilter \
  —enable-decoders \
  —enable-demuxers \
  —enable-encoders \
  —enable-filters \
  —enable-indevs \
  —enable-network \
  —enable-parsers \
  —enable-protocols \
  —enable-swscale \
  —enable-gpl \
  —enable-nonfree \
  $ADDITIONAL_CONFIGURE_FLAG

  cd ..