Category Archives: Media Tools

MediaTools: Two samples to capture M-JPEG video into JPEG files and to play JPEG files back

Posted by on May 13, 2010 2 comments

I added two new simple samples for the MediaTools DirectShow filters to demonstrate how to capture M-JPEG video feed, esp. from an IP camera, and write the video frames into sequence of JPEG files. The other sample takes a directory on the input and plays the images back as video. If you are working on certain transformation filter, it is an easy way to make a reference feed and use it for debugging purposes.

The filters behind that empower the sample are described in another post.

RenderHttpMjpegVideoIntoFiles01 sample takes an URL on the input to generate image/jpeg JPEG or multipart/x-mixed-replace M-JPEG stream. For example, it might be http://demo1.stardotcams.com/nph-mjpeg.cgi feed from a demo StarDot Technologies IP camera.

The application will create a new directory to write files into, and will save each new video frame received into new JPEG file.

Z:\MediaTools\Samples\RenderHttpMjpegVideoIntoFiles01\Release>RenderHttpMjpegVideoIntoFiles01.exe http://demo1.stardotcams.com/nph-mjpeg.cgi
URL: http://demo1.stardotcams.com/nph-mjpeg.cgi
Writing to directory: Z:\MediaTools\Samples\RenderHttpMjpegVideoIntoFiles01\Release\2010-05-12 22-07-37
Event: nCode EC_CLOCK_CHANGED 0xD, nParameter1 0x00000000, nParameter2 0x00000000
Event: nCode EC_PAUSED 0xE, nResult 0x00000000, nParameter2 0x00000000
[...]
^C

The application will generate the files and convert media sample time stamps into file time.

RenderHttpMjpegVideoIntoFiles01 Sample Output

The DirectShow graph that implements the operation is the following:

RenderHttpMjpegVideoIntoFiles01 Filter Graph

The other sample RenderJpegFiles01 takes a directory path to look for JPEG files, e.g. generated by previous sample, and pushes them into DirectShow graph as a video feed. File times will be converted [back] to media sample times.

Read more »

MediaTools: Fix for Motion JPEG video

Posted by on October 6, 2009 1 comment

A small fix for M-JPEG video streams retrieved by HTTP Stream Source Filter:

  • Username and password contained in URL are honored for Basic HTTP authentication
  • Correctly parsed HTTP response headers with quotes, e.g.:
    Content-Type: multipart/x-mixed-replace; boundary=“myboundary“

Partial Visual C++ .NET 2008 source code is available from SVN, release binary included.

Audio Oscillogram DirectShow Filter

Posted by on September 18, 2009 1 comment

Unlike video, audio is difficult to troubleshoot in a way that once an issue has been noticed it was dynamic and already in past and it may be difficult to repeat, explain, forward as a screenshot etc. So it needs a visualization in order to check certain specific of the media stream.

Here we go with a Audio Oscillogram Filter, a filter which may be inserted into audio part of the graph, it insists on PCM audio (multichannel is OK, 8 or 16 bits per sample), so decoders might be required upstream and will be automatically inserted.

Once the filter is running, it shows a tool window with a visualization of the waveform coming through. Additionally, it shows a discontinuity sample (that is, a sample with AM_SAMPLE_DATADISCONTINUITY flag)  with a thick read vertical line, and a mismatch (gap or override) in neighboring sample start and stop times with a thin red line.

Alax.Info Audio Oscillogram Filter

Additionally to this, a window provides an option to pop up downstream audio renderer property sheet in order to check/debug rendering statistics, such as buffer fullness and break count (programmatically available via IAMAudioRendererStats interface). Unfortunately Microsoft does not provide a well done proxy/stub pair for this interface and the property page and there is no way to access this property page connecting to graph remotely. Using this filter the property sheet is shown directly from the hosting process and works correctly.

Audio Renderer Properties

A partial Visual C++ .NET 2008 source code is available from SVN, release binary included.

File and Class Summary

Utility.dll

Utility.dll (download) hosts the following classes:

  • DirectShow Filters
    • Audio Oscillogram Filter, to visualize/debug audio data

Class Overview

Audio Oscillogram Filter

The filter visualizes PCM audio data going through in a form of oscillogram.

Remarks

The filter will create a tool window with audio visualization when put into paused/running state. The filter graph should be controlled (IMediaControl) from a GUI aware apartment so that window messages could reach internal filter’s window.

MediaTools: How to manually configure filters to render M-JPEG video stream from an IP camera

Posted by on August 5, 2009 No comments

Media Tools DirectShow Filters can be used to acquire, parse and decoder M-JPEG encoded video stream from an IP camera or a video server, however for a quick start it is necessary to properly register filters on system and create a DirectShow graph.

To register the filters, it is necessary to download DLLs from repository. While Acquisition.dll does not require special prerequisites installed, CodingI.dll is using Intel Integrated Performance Primitives (IPP) version 6.0.0 internally and requires its [at least] redistributables installed before DLLs are being registered using regsvr32.

Intel went further with new releases of IPP, which are incompatible with the version used to build CodingI.dll, so it is version 6.0.0 (in downloads on Intel website: version 6.0 build 0) has to be installed. Note that Intel DLLs from C:\Program Files\Intel\IPP\6.0.0.044\ia32\bin (version 6.0.0.062 is known to be also compatible) need to be on system search path, or copied to C:\Windows\system32 directory.

Once Intel IPP is prepared, it is required to register CodingI.dll using regsvr32. This registers filters and they are available in GraphEdit and for applications. It is important that on the way of constructing graph which renders video using standard video renderers it is required to specify correct resolution for video, or otherwise graph might fail to start with a message “The graph could not change state”, caused by video renderer failure to dynamically change to different (effective) resolution.

To create rendering graph, add Alax.Info HTTP Stream Source Filter from the filter list and provide camera URL in properties, e.g. http://cam15001.miemasu.net/nphMotionJPEG?Kind=1

Adding Alax.Info HTTP Stream Source Filter

Read more »

MediaTools: Tone Source Filter to generate reference audio feed, dual Audio Source Filter and Virtual Audio Capture Device

Posted by on February 28, 2009 No comments

In order to obtain a reference audio source and especially useful for debugging purposes, including:

  • audio input device unrelated to physical device, to avoid conditions when device is already in use by someone else
  • non-zero audio signal which is independent of certain speaker or broadcasting service, including one that makes capture, transmission or rendering issues easily perceptible by human
  • configurable to provide different audio media types, including through well known DirectShow interfaces, such as IAMStreamConfig
  • configurable to present in system as both regular DirectShow Filter, and as an Audio Capture Source which can be enumerated by applications
  • to be able to check how exactly other applications are accessing and configuring audio capture source

I added a new filter to the Media Tools library, a Tone Source Filter. The filter generates PCM Audio data, either infinite sine waveform, or interrupted signal  of requested parameters:

Tone Source Filter General Property Page

The filter accepts connection on PCM media types with flexible sampling rates in range 8 KHz through 200 KHz, 8-bit audio and 1 channel. Media type is also configurable through or, if not configured this way, the first enumerated media type off the Output pin is also configurable through property page and/or persistent setting accessible via private IDispatch derived interface property.

Tone Source Filter Prefered Format Property Page

Additionally, the filter may configured as a system-wide available audio input device, such as for example available to VLC Media Player or Media Player Classic:

VLC Media Player's Option to use Tone Source Filter based device

In order to configure the filter as such device, the library exports function DoToneSourceFilterDevicePropertySheetModal, which can be called using rundll32 utility (“rundll32 Acquisition.dll,DoToneSourceFilterDevicePropertySheetModal” from command line):

Devices Property Page

A partial Visual C++ .NET 2008 source code is available from SVN, release binary included.

File and Class Summary

Acqusition.dll

Acqusition.dll (download) hosts the following classes:

  • DirectShow Filters
    • Tone Source Filter, to generate reference/debug audio data

Class Overview

Tone Source Filter

The filter generates uninterrupted or interrupted reference sine waveform in form of PCM audio data.

Remarks

The hosting library (DLL) exposes DoToneSourceFilterDevicePropertySheetModal function which provides GUI to configure the filter as one or more audio capture source device, which can be enumerated by System Device Enumerator.

MediaTools: HTTP Stream File Renderer Filter and more

Posted by on February 14, 2009 2 comments

In order to better troubleshoot network cameras and other devices, I added a new DirectShow filter to write HTTP response headers and body into a single file, one file (actually a pairs of files, the second file contains UTF-8 formatted HTTP response headers) per HTTP response.

While troubleshootting JPEG artefact issue with I used the following graph:

HTTP Stream File Renderer Filter in Filter Graph

which started M-JPEG streaming from a camera and had entire stream written into Response-01586228-0001-0001-Headers.txt (Headers) and Response-01586228-0001-0001.dat (Data) files, while parsed JPEG frames were also written into individual files and were available for comparison.

Other changes include:

  • new HTTP Stream File Renderer Filter (details are below)
  • attachable media types on internally used memory allocators, which enable filters to effectively reagree media types in running state
  • workaround for Panasonic BL-C140 camera (may be also helpful for other models), details here

There also seems to be a bug in Intel IPP 6.0 JPEG decoder that leaves bottom right image block incorrectly decoded, only when a sequence of images is decoded and the frame is not the first in the sequence.

A partial Visual C++ .NET 2008 source code is available from SVN, release binary included.

Read more »

MediaTools to deliver video from network/IP cameras and video servers into DirectShow environment

Posted by on January 10, 2009 14 comments

I decided to gather DirectShow code and filters related to processing video from network/IP cameras and video servers into a library (in fact, a few libraries) so that it could be easily used for testing, research and other purposes. As time is going to permit, documentation and sample code will be provided, further development will be carried out.

This initial post publishes two libraries (DLLs) which host DirectShow filters to receive JPEG or M-JPEG video from network using HTTP based protocol, decode video with the help of Intel IPP 6.0 library (UMC version of the JPEG implementation), as well as perform additional helpful features, including writing series of frames into .JPG files and emulating video feed from saved .JPG files, conversion filters to obtain video in 24-bit and 32-bit RGB formats, YUY2 and YV12 formats.

File and Class Summary

Acqusition.dll

Acqusition.dll (download) hosts the following classes:

  • DirectShow Filters
    • HTTP Stream Source Filter, to receive HTTP content and deliver into DirectShow environment through output pin
    • JPEG HTTP Stream Parser Filter, to parse HTTP content (typically received from HTTP Stream Source Filter) of image/jpeg and multipart/x-mixed-replace types and output JPEG frames
    • JPEG Multi File Renderer Filter, to write parsed JPEG frames (typically received from JPEG HTTP Stream Parser Filter) into files
    • JPEG Multi File Source Filter, to read JPEG files (typically written by JPEG Multi File Renderer Filter) and stream video into DirectShow environmentto emulate video feed

Acqusition.dll is dependent only on well known DLLs and does not require presence/redistribution of specific dependency files.

CodingI.dll

CodingI.dll (download) hosts the following classes:

  • DirectShow Filters
    • JPEG Frame Decoder Filter, to parse JPEG data and pass frames downstream with a corresponding mediatype provided with VIDEOINFOHEADER format and correct resolution; in case of resolution changes the filter is capable of dynamically re-agreeing media type with downstream peer
    • JPEG Decoder Filter, to decode JPEG data into 24-bit/32-bit RGB (unfortunately Intel IPP codec has limited capabilities of decoding video into YUV pixel formats)
    • YUY2 Encoder Filter, to convert RGB data into YUY2 pixel format
    • YV12 Encoder Filter, to convert RGB data into YV12 pixel format
  • Shell Extensions
    • JPEG File Resolution Shell Property Page, to provide additional information (such as sampling, color format, resolution) about .JPG and .JPEG files through a shell property page

CodingI.dll is dependent on Intel IPP 6.0 library DLLs and relies on availability of these dependencies in the system. For the CodingI.dll to be operationable, it is required to have a free, trial or registered version of Intel IPP library installed. In particular, the files that are sufficient to be present/redistributed are:

  • libguide40.dll, libiomp5md.dll
  • ippcore-6.0.dll
  • ippi-6.0.dll, ippj-6.0.dll, ipps-6.0.dll, ippcc-6.0.dll, ippvc-6.0.dll
  • ippipx-6.0.dll, ippjpx-6.0.dll, ippspx-6.0.dll, ippccpx-6.0.dll, ippvcpx-6.0.dll

Quick Usage Example

Given a M-JPEG compatible network camera on IP address 98.76.54.32, the graph constructed as shown below is capable to deliver video data and render it through standard Video Mixing Renderer Filter.

Assume the camera is StarDot NetCam SC series, with /jpeg.cgi HTTP request to query for JPEG image and /nph-mjpeg.cgi HTTP request to query for M-JPEG video feed.

To construct the graph in GraphEdit (GraphStudio), first it is required to manually add Alax.Info HTTP Stream Source Filter and provide HTTP URL for the request in the property page:

Then an Alax.Info JPEG HTTP Stream Parser Filter is added and connected downstream to the previously added source filter:

A this point it is possible to automatically render output pin and DirectShow intelligent connect will add the rest of required filters, Alax.Info JPEG Frame Decoder (I), Alax.Info JPEG Decoder (I) and Video Renderer.

However, in order for the graph to run in GraphEdit it is required to manually provide correct video resolution in the properties of JPEG Frame Decoder Filter and once applied reconnect all downstream connections up to video renderer in order to enforce new media type.

Running the graph will start streaming video.

Class Overview

HTTP Stream Source Filter

The filter sends one or series of HTTP requests to receive data from network location and stream received data into DirectShow environment.

Read more »