Use the `-f` parameter to tell ffmpeg which output-format to use. E.g

    ffmpeg -i input.mpg ... -f mp4 output.mp4


I created a table `tbl_Candidate`, but I forgot to set the primary key to the table and I saved it without primary key.

Next time I&#39;m going to set primary key in SQL Server 2008 Express, I get a message like I have to drop the table and recreate when I&#39;m going to save the table with primary key changes.

This is the message that pops up when I&#39;m trying to save changes in the table:

&gt; Saving changes is not permitted. The changes you have made require
&gt; that the following tables to dropped and recreate. You have either made
&gt; changes to the table that can&#39;t be recreate or enable the option
&gt; prevent saving changes that require the tables to be recreate

I&#39;m logged into SQL Server with Windows authentication, server type as database engine and Server name as `.\SQLExpress`.

Please give me a way to correct this problem or way to change the settings of the SQL Server.

Can&#39;t change table design in SQL Server 2008

I am currently furiously digging through all the docs, and haven&#39;t quite found what I&#39;m looking for. I suspect it is a real d&#39;oh! answer.

I simply need to find the active storyboard in the main bundle, and want to know the best way to do this.

This is so that I can use the &lt;code&gt;[UIStoryboard storyboardWithName:@&quot;XXX&quot; bundle:mainBundle]&lt;/code&gt; to extract the running storyboard.

I know how to kludge it by switching on the idiom, but I feel that this is a...kludge.

What&#39;s a correct way of doing this?

UIStoryboard: What&#39;s the Correct Way to Get the Active Storyboard?

I&#39;m developing a system which needs to store videos in the form:

    /path/to/video/&lt;md5 of the file&gt;

So I do not have an output extension.
I&#39;m using `ffmpeg` to convert those videos, but it seems that it uses output file extension to determine the output format, so here&#39;s my problem.

Due to the fact I don&#39;t have an output extension in file names, is there a way to specify the output format directly in the command line without create temporary files or dirty solutions like this ?

FFmpeg output file format with no extension

I'm developing a system which needs to store videos in the form:
<pre><code class="hljs language-css">/path/to/video/&#x3C;md5 of the file>
</code></pre>
So I do not have an output extension.
I'm using <code>ffmpeg</code> to convert those videos, but it seems that it uses output file extension to determine the output format, so here's my problem.
Due to the fact I don't have an output extension in file names, is there a way to specify the output format directly in the command line without create temporary files or dirty solutions like this ?

I have two applications as mentioned below:

 1. Admin application  through which I am able to upload a .mp4 file to the server.
 2. I am trying to download the .mp4 using mobile application in iPad.

***

 - The Admin application is made by using asp.net 4.0 and SQL Server, IIS7.
 - The Mobile application is made of asp.net mvc3, jquerymobile, HTML5.

As of now I have added mime type `video/mp4` for .mp4 in IIS7 mime types section.

When I am trying to download the .mp4 file in iPad I am seeing a dark black screen with cross arrow on it. Can anyone please help me to resolve the issue.

Please tell me whether the mime type `video/mp4` for .mp4 is correct.

Correct mime type for .mp4

Currently I am using this command to extract the images:

    ffmpeg -i input.mp4 output_%03d.jpeg

But how can I improve the JPEG image quality?

How can I extract a good quality JPEG image from a video file with ffmpeg?

I&#39;m trying to setup a very basic html5 page that loads a .mp4 video that is 20MB.  It appears that the browser needs to download the entire thing rather than just playing the first part of the video and streaming in the rest.

[This post][1] is the closest thing I&#39;ve found while searching... I tried both Hand Brake and Data Go Round by neither appeared to make a difference: 

Any ideas on how to do this or if it&#39;s possible?

Here is the code I&#39;m using:

&lt;!-- language: lang-html --&gt;

    &lt;video controls=&quot;controls&quot;&gt;
        &lt;source src=&quot;/video.mp4&quot; type=&quot;video/mp4&quot; /&gt;
        Your browser does not support the video tag.
    &lt;/video&gt;


  [1]: https://stackoverflow.com/questions/6683418/inline-video-large-file-with-buffer

HTML5 - How to stream large .mp4 files?

I&#39;m looking to place a video in an HTML5 page that will begin playing on page-load, and once completed, loop back to the beginning without a break. The video should also **NOT** have any controls associated with it, and either be compatible with all &#39;modern&#39; browsers, or have the option of a polyfill.

Previously I would have done this via `Flash` and `FLVPlayback`, but I would prefer to steer clear of `Flash` in the HTML5 sphere. I&#39;m thinking I could use javascript&#39;s `setTimeout` to create a smooth loop, but what should I use to embed the video itself? Is there something out there that will stream the video the way `FLVPlayback` would?

Play infinitely looping video on-load in HTML5

     private void StartReceivingData(string ipAddress, int iPort)
        {
            try
            {
                if (!_bContinueReciving)
                {
                    //initializeMainSocket(ipAddress, iPort);
                    _mSocket = new Socket(AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.IP);//&lt;------HERE IS RAISED THE EXCEPTION
                    _mSocket.Bind(new IPEndPoint(IPAddress.Parse(ipAddress), iPort));
                    //  _mSocket.Bind(new IPEndPoint(IPAddress.Loopback, iPort));
                    _mSocket.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.HeaderIncluded, true);
                    _mSocket.IOControl(IOControlCode.ReceiveAll, new byte[4] { 1, 0, 0, 0 }, new byte[4] { 0, 0, 0, 0 });
                    //var 1
                    _mSocket.BeginReceive(_buffReceivedData, 0, _buffReceivedData.Length, SocketFlags.None,
                                         new AsyncCallback(OnReceive), null);
                    initializeLocalSocket();
                }
                else
                {
                    _bContinueReciving = false;
                    _mSocket.Close();
                }
            }
            catch (Exception exception)
            {
                Debug.WriteLine(exception);
            }
        }

I don&#39;t understand why...it worked and now it doesn&#39;t. could someone help me?
i am streaming with vlc, and i wan&#39;t to receive the packets, do some reports, and then restream local to a player 

An attempt was made to access a socket in a way forbidden by its access permissions. Why?

I tried the following command to extract audio from video:

    ffmpeg -i Sample.avi -vn -ar 44100 -ac 2 -ab 192k -f mp3 Sample.mp3

but I get the following output

    libavutil     50.15. 1 / 50.15. 1
    libavcodec    52.72. 2 / 52.72. 2
    libavformat   52.64. 2 / 52.64. 2
    libavdevice   52. 2. 0 / 52. 2. 0
    libavfilter    1.19. 0 /  1.19. 0
    libswscale     0.11. 0 /  0.11. 0
    libpostproc   51. 2. 0 / 51. 2. 0
    SamplE.avi: Invalid data found when processing input

Can anyone help, please?


How can I extract audio from video with ffmpeg?

I am currently using these commands:

    Top left corner
    ffmpeg –i inputvideo.avi -vf &quot;movie=watermarklogo.png [watermark]; [in][watermark] overlay=10:10 [out]&quot; outputvideo.flv
    
    Top right corner
    ffmpeg –i inputvideo.avi -vf &quot;movie=watermarklogo.png [watermark]; [in][watermark] overlay=main_w-overlay_w-10:10 [out]&quot; outputvideo.flv
    
    Bottom left corner
    ffmpeg –i inputvideo.avi -vf &quot;movie=watermarklogo.png [watermark]; [in][watermark] overlay=10:main_h-overlay_h-10 [out]&quot; outputvideo.flv
    
    Bottom right corner
    ffmpeg –i inputvideo.avi -vf &quot;movie=watermarklogo.png [watermark]; [in][watermark] overlay=(main_w-overlay_w-10)/2:(main_h-overlay_h-10)/2 [out]&quot; outputvideo.flv

How to place watermark center of the video ?

How to add transparent watermark in center of a video with ffmpeg?

Hi I need to extract frames from videos using ffmpeg.. Is there a faster way to do it than this:

    ffmpeg -i file.mpg -r 1/1 $filename%03d.jpg

?

Fastest way to extract frames using ffmpeg?

when i run 

    ffmpeg -y -i test.mov -threads 8 -f webm -aspect 16:9 -vcodec libvpx -deinterlace -g 120 -level 216 -profile 0 -qmax 42 -qmin 10 -rc_buf_aggressivity 0.95 -vb 2M -acodec libvorbis -aq 90 -ac 2 OUTPUT_FILE.webm

it returns an error saying `Unknown encoder &#39;libvpx&#39;`

I installed libvpx, libvorbis, libogg, and ffmpeg all via macports


ffmpeg unable to find encoder libvpx

Are these both the same? Is H.264 codec of MPEG-4? What if I need to convert flv to high definition H.264 video format? I want make online tv streaming and want to use PHP or Python.

What is the difference between H.264 video and MPEG-4 video?

I&#39;m looking for a way to rotate videos shot with my Nexus 4 on my Debian Wheezy sytem. The videos are shot in portrait mode and I would like to rotate them to landscape mode. Preferably the rotation is command-line driven.

I have found several previous questions which are hinting at a good solution but I can&#39;t seem to manage to get it working.

To begin with there was this question:
https://stackoverflow.com/questions/3937387/rotating-videos-with-ffmpeg

But it indicates that ffmpeg is outdated and that I should use avconv. I found this question detailing the way to go forward.
https://askubuntu.com/questions/269429/how-can-i-rotate-video-by-180-degrees-with-avconv

This made me using following command:

    avconv -i original.mp4 -vf &quot;transpose=1&quot; -codec:v libx264 -preset slow -crf 25 -codec:a copy flipped.mp4

However, this is painstakingly slow (last test took me more than 6 hours for less than 3 minutes of footage) and does not result in a playable movie. I also get an error in logging output which states Mb Rate &gt; level limit.

Is there an issue here with the re-encoding? Should I first re-encode the videos from my phone to another, more &quot;workable&quot; encoding before applying the rotations? Or am I missing another important point?

Rotate mp4 videos without re-encoding

I&#39;ve been struggling with this issue for more than a week, and most likely it is a bug in the **Qualcomm GPU/hardware video encoder**. Since we are pressed to release the application, and their developer forums did not provide any feedback, I am posting it here too, hoping that someone is able to provide some clues, or even better, a workaround so that the bug in the encoder is not triggered.
 
The application encodes from a Surface. When certain images are rendered to the surface, the encoder fails (100%) in the same place (when the frame currently being encoded is a key frame). The Logcat output from the encoder at the point of the crash is(with the last lines repeated at a very high rate):

    11-26 11:41:33.312: E/OMX-VENC-720p(25949): ERROR: async_msg_process() - Error statuscode = 1
    11-26 11:41:33.312: E/ACodec(29317): [OMX.qcom.video.encoder.avc] ERROR(0x80001009)
    11-26 11:41:33.312: E/MediaCodec(29317): Codec reported an error. (omx error 0x80001009, internalError -2147483648)
    11-26 11:41:33.362: E/OMX-VENC-720p(25949): ERROR: venc_use_buf:set input buffer failed 
    11-26 11:41:33.362: E/OMX-VENC-720p(25949): ERROR: in dev_use_buf
    11-26 11:41:33.362: E/OMX-VENC-720p(25949): ERROR: empty_buffer_done() failed!
    11-26 11:41:33.372: E/OMX-VENC-720p(25949): m_fbd_count at o/p flush = 306
    11-26 11:41:33.372: E/OMX-VENC-720p(25949): m_etb_count at i/p flush = 313
    11-26 11:41:33.372: E/OMX-VENC-720p(25949): ERROR: ioctl VEN_IOCTL_CMD_FILL_OUTPUT_BUFFER failed
    11-26 11:41:33.372: E/OMX-VENC-720p(25949): ERROR: dev_fill_buf() Failed
    11-26 11:41:33.372: E/OMX-VENC-720p(25949): ERROR: FTBProxy() failed!

I can replicate it also on [Grafika][1] by simply replacing in the _Record GL app_ the drawing of two geometric forms with drawing one of the problematic images, full screen, in landscape mode, and changing the bitrate to a higher value (7Mbps).
The crash of the encoder happens sooner for larger bitrate.

Here is one [image][2] that seems to break it easily and here is [RecordFBOActivity.java][3] with the required changes. 

With Grafika, I tested and the encoder crashes on both Samsung S4, international version, and on the original Nexus 4. With our software, which is a little more complex than rendering the plain image, it still crashes on both. Did not test on any other Adreno devices. On Samsung S3, with a Mali 400 GPU, it works fine.

At 4Mbps, the encoder in our application still crashes on both S4 and N4, but later. Grafika crashes on N4 in the same place, but not on S4.

EDIT: According to comments bellow, it can be reproduced also when encoding the same image from the buffer. Various tests seem to narrow the conditions to reproduce it at: h264 hw encoder on Qualcomm devices, encoding a still image for many frames (this determines very low bitrates in the encoder due to similar frames), error appearing while encoding a key frame (the error appears only when encoding certain images, which seem to have more detail, i.e. need many bits for intra coding).


  [1]: https://github.com/google/grafika
  [2]: http://turl.ca/tqzs
  [3]: http://pastebin.com/gYXn5UWa

Encoder crash on Adreno GPU while encoding from Surface

Situation:
----------
I am trying to export video with some parameters like video bit rate, audio bit rate, frame rate, changing video resolution, etc. Note that I am letting the user set the video frame rate in fractions; like user can set the video frame rate say, 23.98.

I use **AVAssetWriter** and **AVAssetReader** for this operation. I use [AVAssetWriterInputPixelBufferAdaptor][1] for writing the sample buffers.

Everything else works just fine, except the **video frame rate**.


What I have tried:
------------------

 1. Setting the **AVAssetWriter.movieTimeScale** as suggested [here][2]. Which does change the video frame rate but also makes the video sluggish. ([gist here][3])

----------
 2. Setting **AVVideoExpectedSourceFrameRateKey**. Which does not help. ([gist here][4])

----------
 3. Setting **AVAssetWriterInput.mediaTimeScale**. Again, it changes the video frame rate but makes the video sluggish as *AVAssetWriter.movieTimeScale* does. The video shows different frames at some point and sometimes it sticks and resumes again. ([gist here][5])

----------
 4. Using **AVAssetReaderVideoCompositionOutput** and setting **AVMutableVideoComposition.frameDuration**; just like [SDAVAssetExportSession][6] does. Ironically with SDAVAssetExportSession code, the video is being exported just at the right frame rate that I want, but it just does not work in my code. [gist here][7]

I am not sure why it won&#39;t work with my code. The issue with this approach is it always returns nil from *AVAssetReaderVideoCompositionOutput.copyNextSampleBuffer()*.

----------
 5. Manually changing the timestamp of the frame with **CMSampleTimingInfo**, as suggested [here][8] Something like:

```
var sampleTimingInfo = CMSampleTimingInfo()
var sampleBufferToWrite: CMSampleBuffer?

CMSampleBufferGetSampleTimingInfo(vBuffer, at: 0, timingInfoOut: &amp;sampleTimingInfo)

sampleTimingInfo.duration = CMTimeMake(value: 100, timescale: Int32(videoConfig.videoFrameRate * 100))

sampleTimingInfo.presentationTimeStamp = CMTimeAdd(previousPresentationTimeStamp, sampleTimingInfo.duration)

previousPresentationTimeStamp = sampleTimingInfo.presentationTimeStamp

let status = CMSampleBufferCreateCopyWithNewTiming(allocator: kCFAllocatorDefault, sampleBuffer: vBuffer,sampleTimingEntryCount: 1, sampleTimingArray: &amp;sampleTimingInfo, sampleBufferOut: &amp;sampleBufferToWrite)
```
With this approach, I do get the frame rate set just right, but it increases the video duration (as mentioned in the comment of that question’s answer). I think at some point I may have to discard some frames (if the target frame rate is lower; I need to lower the frame rate in most of the cases). 

If I know that if I want 30fps, and my current frame rate is 60fps, it&#39;s simple to discard every second frame and setting the SampleBuffer time accordingly.

If I go with this approach(i.e. setting 23.98 fps), how do I decide which frame to discard and if the target frame rate is higher, which frame to duplicate? Reminder: the frame rate could be in fractions.

----------


  [1]: https://developer.apple.com/documentation/avfoundation/avassetwriterinputpixelbufferadaptor
  [2]: https://stackoverflow.com/a/16911799/1208191
  [3]: https://gist.github.com/chauhan130/31b8bf648f0071a949d1627c78315056#file-gistfile1-txt-L16
  [4]: https://gist.github.com/chauhan130/31b8bf648f0071a949d1627c78315056#file-gistfile1-txt-L38
  [5]: https://gist.github.com/chauhan130/31b8bf648f0071a949d1627c78315056#file-gistfile1-txt-L50
  [6]: https://github.com/rs/SDAVAssetExportSession
  [7]: https://gist.github.com/chauhan130/8d2f5bbe680353961fecacb80e254b92#file-gistfile1-txt-L77
  [8]: https://stackoverflow.com/a/49236475/1208191

Content Type	Original Author	Original Content on Stackoverflow
Question	Simone Margaritelli	View Question on Stackoverflow
Solution 1 - Video	luukes	View Answer on Stackoverflow

FFmpeg output file format with no extension

Video Problem Overview

Video Solutions

Solution 1 - Video

UIStoryboard: What's the Correct Way to Get the Active Storyboard?

Can't change table design in SQL Server 2008

Attributions