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• Encoding video settings with Transloadit and FFMPEG

  2 octobre 2015, par David Soler

  I’m using Transloadit to convert and compress videos from .mov to .ts format. I’m using the json templates but unfortunately the docs are not too extensive. The thing is the quality I’m getting rigth now is very poor and pixeled. If I do it through console with ffmpeg command and including some parameters as crf (Constant Rate Factor) the quality gets a lot better but I dont know how edit it in transloadit template to get the same result.

  This is the ffmpeg command I’m using to convert the video in console

  ./ffmpeg -i ../canales.mov -c:v libx264 -crf 23 -bsf:a aac_adtstoasc output.ts

  And this is the json template I’m using right now. I guess I should add parameters to ffmpeg hash but I don’t know which settings are allowed

  {
  
    "steps": {
  
      "file": {
  
        "robot": "/file/filter",
  
        "accepts": [
  
          [
  
            "${file.mime}",
  
            "regex",
  
            "video"
  
          ]
  
        ],
  
        "declines": [
  
          [
  
            "${file.size}",
  
            ">",
  
            "10485760"
  
          ],
  
          [
  
            "${file.meta.duration}",
  
            ">",
  
            "16"
  
          ]
  
        ],
  
        "error_on_decline": true
  
      },
  
      "segments": {
  
        "robot": "/video/encode",
  
        "preset": "iphone-high",
  
        "width": 1242,
  
        "height": 2208,
  
        "use": "file",
  
        "segment": true,
  
        "segment_duration": 10,
  
        "ffmpeg_stack": "v2.2.3",
  
        "ffmpeg": {
  
          "b": "1200K",
  
          "crf": 23
  
        }
  
      },
  
      "thumb": {
  
        "robot": "/video/thumbs",
  
        "use": "file",
  
        "count": 1
  
      },
  
      "store": {
  
        "robot": "/s3/store",
  
        "use": [
  
          "segments",
  
          "thumb"
  
        ],
  
        "key": "key",
  
        "secret": "Secret",
  
        "bucket": "bucket"
  
      }
  
    }
  
  }

• Building FFMPEG library for iOS6.0 ARMv7 Processor

  15 août 2013, par Jimmy

  WARNING :

  I was just informed by another user that there are some legal issues revolving around using FFMPEG for iOS, leaving the link here http://multinc.com/2009/08/24/compatibility-between-the-iphone-app-store-and-the-lgpl/

  I cleaned up my question a little bit, when I wrote it the first time I was flustered. Now I can be more clear after taking a small break.

  Edit : learned that you have to build for ARMv7, ARMv7s and iOS6.0

  I'm trying to use the FFMPEG library in an XCode 4.5.1 project. And I'm trying to build it for ARMv7. What I'm looking for is the exact process, and some explanation. I understand that this is not a well documented problem. But I know that other pople have had the same problem as me.

  What I have been able to do.

  I have been able to build the library for testing.

  1) I have been able to clone ffmpeg. For beginners this will get you started by creating a directory with the ffmpeg source. (Kudos to the guys who wrote it)

  git clone git ://source.ffmpeg.org/ffmpeg.git ffmpeg

  2) I have been able to write a config file that doesn't have any errors. We will go back to this part later. This is the command I attach to ./configure

  ./configure
  —disable-doc
  —disable-ffmpeg
  —disable-ffplay
  —disable-ffserver
  —enable-cross-compile
  —arch=arm
  —target-os=darwin
  —cc=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/llvm-gcc-4.2/bin/arm-apple-darwin10-llvm-gcc-4.2

  —as='gas-preprocessor/gas-preprocessor.pl /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/llvm-gcc-4.2/bin/arm-apple-darwin10-llvm-gcc-4.2'

  —sysroot=/applications/xcode.app/contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk

  —cpu=cortex-a8
  —extra-ldflags='-arch=armv7 -isysroot /applications/xcode.app/contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk'
  —enable-pic —disable-bzlib —disable-gpl —disable-shared —enable-static —disable-mmx —disable-debug —disable-neon —extra-cflags='-pipe -Os -gdwarf-2 -isysroot /applications/xcode.app/contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.1.sdk
  -m$thumb_opt :-no-thumb -mthumb-interwork'

  These are some things to note.

  • I had to download ( https://github.com/yuvi/gas-preprocessor ) copy the file gas-preprocessor.pl at /usr/local/bin. Set permissions to read write (777)
  • Make sure I'm using the right GCC compiler : /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/llvm-gcc-4.2/bin/arm-apple-darwin10-llvm-gcc-4.2
  • Make sure I'm using the right SDK : /applications/xcode.app/contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk
  • —extra-cflags="-arch armv7" causes : error : unrecognized command line option “-arch”

  Here in lies the problem.

  I can include the library like so

  libavcodec/avcodec.h

  But when I started to write the encoder. I received this warning, and countless errors.

  ignoring file /Users/Jimmy/Development/source.ffmpeg/Library/libavutil.a, file was built for archive which is not the architecture being linked (armv7s) : /Users/Jimmy/Development/source.ffmpeg/Library/libavutil.a

  That means that I didn't build the right binary.

  What I'm looking for is someone whose done it before, to walk all of us through the process of building FFMPEG for iOS6.0 and ARMv7 and the majority of things to look out for. Thanks a ton.

• FFmpeg does not decode h264 stream

  5 juillet 2012, par HAPPY_TIGER

  I am trying to decode h264 stream from rtsp server and render it on iPhone.

  I found some libraries and read some articles about it.

  Libraries are from dropCam for iPhone called RTSPClient and DecoderWrapper.

  But I can not decode frame data with DecodeWrapper that using on ffmpeg.

  Here are my code.

  VideoViewer.m
  
  
  
  - (void)didReceiveFrame:(NSData*)frameData presentationTime:(NSDate*)presentationTime
  
  {
  
      [VideoDecoder staticInitialize];
  
      mConverter = [[VideoDecoder alloc] initWithCodec:kVCT_H264 colorSpace:kVCS_RGBA32 width:320 height:240 privateData:nil];
  
  
  
  
  
      [mConverter decodeFrame:frameData];
  
  
  
      if ([mConverter isFrameReady]) {
  
          UIImage *imageData =[mConverter getDecodedFrame];
  
          if (imageData) {
  
              [mVideoView setImage:imageData];
  
              NSLog(@"decoded!");
  
          }
  
      }
  
  }
  
  
  
  ---VideoDecoder.m---
  
  - (id)initWithCodec:(enum VideoCodecType)codecType 
  
           colorSpace:(enum VideoColorSpace)colorSpace 
  
                width:(int)width 
  
               height:(int)height 
  
          privateData:(NSData*)privateData {
  
      if(self = [super init]) {
  
  
  
          codec = avcodec_find_decoder(CODEC_ID_H264);
  
          codecCtx = avcodec_alloc_context();
  
  
  
          // Note: for H.264 RTSP streams, the width and height are usually not specified (width and height are 0).  
  
          // These fields will become filled in once the first frame is decoded and the SPS is processed.
  
          codecCtx->width = width;
  
          codecCtx->height = height;
  
  
  
          codecCtx->extradata = av_malloc([privateData length]);
  
          codecCtx->extradata_size = [privateData length];
  
          [privateData getBytes:codecCtx->extradata length:codecCtx->extradata_size];
  
          codecCtx->pix_fmt = PIX_FMT_RGBA;
  
  #ifdef SHOW_DEBUG_MV
  
          codecCtx->debug_mv = 0xFF;
  
  #endif
  
  
  
          srcFrame = avcodec_alloc_frame();
  
          dstFrame = avcodec_alloc_frame();
  
  
  
          int res = avcodec_open(codecCtx, codec);
  
          if (res < 0)
  
          {
  
              NSLog(@"Failed to initialize decoder");
  
          }
  
  
  
      }
  
  
  
      return self;    
  
  }
  
  
  
  - (void)decodeFrame:(NSData*)frameData {
  
  
  
  
  
      AVPacket packet = {0};
  
      packet.data = (uint8_t*)[frameData bytes];
  
      packet.size = [frameData length];
  
  
  
      int frameFinished=0;
  
      NSLog(@"Packet size===>%d",packet.size);
  
      // Is this a packet from the video stream?
  
      if(packet.stream_index==0)
  
      {
  
          int res = avcodec_decode_video2(codecCtx, srcFrame, &frameFinished, &packet);
  
          NSLog(@"Res value===>%d",res);
  
          NSLog(@"frame data===>%d",(int)srcFrame->data);
  
          if (res < 0)
  
          {
  
              NSLog(@"Failed to decode frame");
  
          }
  
      }
  
      else 
  
      {
  
          NSLog(@"No video stream found");
  
      }
  
  
  
  
  
      // Need to delay initializing the output buffers because we don't know the dimensions until we decode the first frame.
  
      if (!outputInit) {
  
          if (codecCtx->width > 0 && codecCtx->height > 0) {
  
  #ifdef _DEBUG
  
              NSLog(@"Initializing decoder with frame size of: %dx%d", codecCtx->width, codecCtx->height);
  
  #endif
  
  
  
              outputBufLen = avpicture_get_size(PIX_FMT_RGBA, codecCtx->width, codecCtx->height);
  
              outputBuf = av_malloc(outputBufLen);
  
  
  
              avpicture_fill((AVPicture*)dstFrame, outputBuf, PIX_FMT_RGBA, codecCtx->width, codecCtx->height);
  
  
  
              convertCtx = sws_getContext(codecCtx->width, codecCtx->height, codecCtx->pix_fmt,  codecCtx->width, 
  
                                          codecCtx->height, PIX_FMT_RGBA, SWS_FAST_BILINEAR, NULL, NULL, NULL); 
  
  
  
              outputInit = YES;
  
              frameFinished=1;
  
          }
  
          else {
  
              NSLog(@"Could not get video output dimensions");
  
          }
  
      }
  
  
  
      if (frameFinished)
  
          frameReady = YES;
  
  
  
  }

  The console shows me as follows.

  2011-05-16 20:16:04.223 RTSPTest1[41226:207] Packet size===>359
  
  [h264 @ 0x5815c00] no frame!
  
  2011-05-16 20:16:04.223 RTSPTest1[41226:207] Res value===>-1
  
  2011-05-16 20:16:04.224 RTSPTest1[41226:207] frame data===>101791200
  
  2011-05-16 20:16:04.224 RTSPTest1[41226:207] Failed to decode frame
  
  2011-05-16 20:16:04.225 RTSPTest1[41226:207] decoded!
  
  2011-05-16 20:16:04.226 RTSPTest1[41226:207] Packet size===>424
  
  [h264 @ 0x5017c00] no frame!
  
  2011-05-16 20:16:04.226 RTSPTest1[41226:207] Res value===>-1
  
  2011-05-16 20:16:04.227 RTSPTest1[41226:207] frame data===>81002704
  
  2011-05-16 20:16:04.227 RTSPTest1[41226:207] Failed to decode frame
  
  2011-05-16 20:16:04.228 RTSPTest1[41226:207] decoded!
  
  2011-05-16 20:16:04.229 RTSPTest1[41226:207] Packet size===>424
  
  [h264 @ 0x581d000] no frame!
  
  2011-05-16 20:16:04.229 RTSPTest1[41226:207] Res value===>-1
  
  2011-05-16 20:16:04.230 RTSPTest1[41226:207] frame data===>101791616
  
  2011-05-16 20:16:04.230 RTSPTest1[41226:207] Failed to decode frame
  
  2011-05-16 20:16:04.231 RTSPTest1[41226:207] decoded!
  
  . . . .  .

  But the simulator shows nothing.

  What's wrong with my code.

  Help me solve this problem.

  Thanks for your answers.