The pipeline below works fine for saving compressed JPEG images but is there a way to save lossless compressed JPEG images using gstreamer?
gst-launch v4l2src always-copy=false num-buffers=1 chain-ipipe=true ! 'video/x-raw-yuv,format=(fourcc)NV12, width=2176, height=1944' ! dmaiaccel ! dm365facedetect draw-square=true ! dmaienc_jpeg ! filesink location=$FILE_NAME
Assuming you have all the GStreamer plugins installed (good, bad, and ugly), you have an impressive number of lossless video compressors at your disposal via the FFmpeg GStreamer element. These include ffenc_png (for PNG encoding), ffenc_jpegls (lossless JPEG algorithm), and many less common ones.
However, if I'm reading your GStreamer command line correctly, you seem to be calling a series of custom components that are tied to a particular type of hardware (I have been Googling but I haven't quite nailed down what it is). The JPEG encoder component is 'dmaienc_jpeg'. It's possible that the element preceding it in the chain (dm365facedetect) only outputs data that dmaienc_jpeg can interpret. However, if it's a general colorspace, then you can send it through an FFmpeg lossless encoder, possibly with a colorspace conversion in between. The answer can be ascertained by invoking 'gst-inspect' on the elements and studying the output (the src and sink data types).
Update, pursuant to new data: Good news: that dm365facedetect element outputs raw YUV in an NV12 format. Very flexible, and you have a lot of options.
What platform are you on? If you are using Ubuntu Linux, install a bunch of GStreamer plugins using:
apt-get install gstreamer0.10-plugins-good \
gstreamer0.10-plugins-bad gstreamer0.10-plugins-ugly gstreamer0.10-ffmpeg
Some lossless codec options: PNG, via either 'pngenc' or 'ffenc_png' (although this may technically incur a tiny bit of loss due to YUV -> RGB colorspace conversion), 'ffenc_huffyuv', 'ffenc_jpegls', or 'ffenc_ljpeg'. When you encode these, send them through the avimux component. So, an example amendment to the end of your command line:
... ! dm365facedetect draw-square=true ! ffenc_ljpeg ! \
avimux ! filesink location=$FILE_NAME
Expect the lossless codec data to be somewhat larger than the JPEG data you were getting before. Experiment with different codecs to see what you like, and make sure you can decode the data on the other side using your preferred toolchain (FFmpeg and VLC should always be able to handle it).
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I'm attempting to stream a H.264 video feed to a web browser. Media Foundation is used for encoding a fragmented MPEG4 stream (MFCreateFMPEG4MediaSink with MFTranscodeContainerType_FMPEG4, MF_LOW_LATENCY and MF_READWRITE_ENABLE_HARDWARE_TRANSFORMS enabled). The stream is then connected to a web server through IMFByteStream.
Streaming of the H.264 video works fine when it's being consumed by a <video src=".."/> tag. However, the resulting latency is ~2sec, which is too much for the application in question. My suspicion is that client-side buffering causes most of the latency. Therefore, I'm experimenting with Media Source Extensions (MSE) for programmatic control over the in-browser streaming. Chrome does, however, fail with the following error when consuming the same MPEG4 stream through MSE:
Failure parsing MP4: TFHD base-data-offset not allowed by MSE. See
https://www.w3.org/TR/mse-byte-stream-format-isobmff/#movie-fragment-relative-addressing
mp4dump of a moof/mdat fragment in the MPEG4 stream. This clearly shows that the TFHD contains an "illegal" base data offset parameter:
[moof] size=8+200
[mfhd] size=12+4
sequence number = 3
[traf] size=8+176
[tfhd] size=12+16, flags=1
track ID = 1
base data offset = 36690
[trun] size=12+136, version=1, flags=f01
sample count = 8
data offset = 0
[mdat] size=8+1624
I'm using Chrome 65.0.3325.181 (Official Build) (32-bit), running on Win10 version 1709 (16299.309).
Is there any way of generating a MSE-compatible H.264/MPEG4 video stream using Media Foundation?
Status Update:
Based on roman-r advise, I managed to fix the problem myself by intercepting the generated MPEG4 stream and perform the following modifications:
Modify Track Fragment Header Box (tfhd):
remove base_data_offset parameter (reduces stream size by 8bytes)
set default-base-is-moof flag
Add missing Track Fragment Decode Time (tfdt) (increases stream size by 20bytes)
set baseMediaDecodeTime parameter
Modify Track fragment Run box (trun):
adjust data_offset parameter
The field descriptions are documented in https://www.iso.org/standard/68960.html (free download).
Switching to MSE-based video streaming reduced the latency from ~2.0 to 0.7 sec. The latency was furthermore reduced to 0-1 frames by calling IMFSinkWriter::NotifyEndOfSegment after each IMFSinkWriter::WriteSample call.
There's a sample implementation available on https://github.com/forderud/AppWebStream
I was getting the same error (Failure parsing MP4: TFHD base-data-offset not allowed by MSE) when trying to play a fmp4 via MSE. The fmp4 had been created from a mp4 using the following ffmpeg comand:
ffmpeg -i myvideo.mp4 -g 52 -vcodec copy -f mp4 -movflags frag_keyframe+empty_moov myfmp4video.mp4
Based on this question I was able to find out that to have the fmp4 working in Chrome I had to add the "default_base_moof" flag. So, after creating the fmp4 with the following command:
ffmpeg -i myvideo.mp4 -g 52 -vcodec copy -f mp4 -movflags frag_keyframe+empty_moov+default_base_moof myfmp4video.mp4
I was able to play successfully the video using Media Source Extensions.
This Mozilla article helped to find out that missing flag:
https://developer.mozilla.org/en-US/docs/Web/API/Media_Source_Extensions_API/Transcoding_assets_for_MSE
The mentioned 0.7 sec latency (in your Status Update) is caused by the Media Foundation's MFTranscodeContainerType_FMPEG4 containterizer which gathers and outputs each roughly 1/3 seconds (from unknown reason) of frames in one MP4 moof/mdat box pair. This means that you need to wait 19 frames before getting any output from MFTranscodeContainerType_FMPEG4 at 60 FPS.
To output single MP4 moof/mdat per each frame, simply lie that MF_MT_FRAME_RATE is 1 FPS (or anything higher than 1/3 sec). To play the video at the correct speed, use Media Source Extensions' <video>.playbackRate or rather update timescale (i.e. multiply by real FPS) of mvhd and mdhd boxes in your MP4 stream interceptor to get the correctly timed MP4 stream.
Doing that, the latency can be squeezed to under 20 ms. This is barely recognizable when you see the output side by side on localhost in chains such as Unity (research) -> NvEnc -> MFTranscodeContainerType_FMPEG4 -> WebSocket -> Chrome Media Source Extensions display.
Note that MFTranscodeContainerType_FMPEG4 still introduces 1 frame delay (1st frame in, no output, 2nd frame in, 1st frame out, ...), hence the 20 ms latency at 60 FPS. The only solution to that seems to be writing own FMPEG4 containerizer. But that is order of magnitude more complex than intercepting of Media Foundation's MP4 streams.
The problem was solved by following roman-r's advise, and modifying the generated MPEG4 stream. See answer above.
Another way to do this is again using the same code #Fredrik mentioned but I write my own IMFByteStream and and I check the chunks written to the IMFByteStream.
FFMpeg writes the atoms almost once at a time. So you can check the atom name and do the mods. It is the same thing. I wish there was an MSE compliant windows sinker.
Is there one that can generate .ts files for HLS?
How to create an Mp4 file from H264 raw data that I am receiving from a live streamer (no predefined duration or moov atom), unfortunately can't use FFMPEG, I have to write my own code using live555. Can somebody help me with Mp4 container and how h264 data has to be pushed into it.? Thank you in advance : )
There are several operations to be made to store H.264 raw data into MP4, among them:
create box structures, in particular the moov box
store the NAL units in a mdatbox, possibly storing non-VCL NAL units in the moovbox
replace start codes with length fields
It also depends on your requirements. If you want to do the conversion on-the-fly, you have to use fragmented mp4. If you can store the H264 and then do the conversion, you may use non-fragmented mp4. In particular using MP4Box:
MP4Box -add file.264 file.mp4
I'm curious as to what file types are used for Motion Industry Standards Board KLV (Key Length Value). I've read the documentation at the MISB site, which is quite huge. It indicates, to my understanding, that MPEG-2, is usually used so I tried to get an idea as to what to look for in file extensions to recognise files that have the capability for embeding KLV metadata.
My question is: If a file has an extension like these - *.TS *.mpg, does that indicate potential KLV embedding? Are there any more types ? Can an active video stream from a camera contain KLV?
Any resonse or elaboration is appreciated. Thanks ahead !
As MISB docs state, only MPEG video streams for full motion video and NITF images for high resolution wide area coverage.
Mostly MPEG-TS streams, AFAIK.
You can scan your files for strings like "KLVA" or some of the keys defined in the standard to quickly detect such files with high confidence.
By scanning the titles of documents on the MISB site, one can glean that KLV can be encoded in AES3 Serial Digital Audio Streams, SMPTE 291 Ancillary Data Packets, and SDP (Session Description Protocol) [streams]. Reading a quick bit of the guidance .pdf also reveals that:
...MPEG-2 Transport Streams are a common multiplexing device for multiple data streams...
...but this does not limit KLV to only the MPEG-2 TS.
As a direct answer to your question: if the KLV stream is contained within an MPEG-2 Transport Stream, then yes - either *.ts or *.mpg files would qualify. (As would any other file capable of storing/containing an MPEG-2 Transport Stream.)
If you have further questions, reach out to me.
I'm trying to convert this RTSP URL to something else (anything!) using this gst pipeline:
gst-launch rtspsrc location=rtsp://184.72.239.149/vod/mp4:BigBuckBunny_175k.mov ! rtpmp4vdepay ! filesink location=somebytes.bin
This gives the following error:
ERROR: from element /GstPipeline:pipeline0/GstRTSPSrc:rtspsrc0/GstUDPSrc:udpsrc0: Internal data flow error.
Additional debug info:
gstbasesrc.c(2791): gst_base_src_loop (): /GstPipeline:pipeline0/GstRTSPSrc:rtspsrc0/GstUDPSrc:udpsrc0:
streaming task paused, reason not-linked (-1)
So I guess it's something about connecting the rstp source to the depayloader. If I change the pipeline to use rtpmp4gdepay rather than vdepay, it works and produces something, but I'm not sure what the output format is.
Does anyone know what pipeline I should be using to get at the video from this URL? I'm assuming it's mp4/h264/aac, but maybe it's not.
Try this first:
gst-launch-0.10 -v playbin2 uri=rtsp://184.72.239.149/vod/mp4:BigBuckBunny_175k.mov
or
gst-launch-1.0 -v playbin uri=rtsp://184.72.239.149/vod/mp4:BigBuckBunny_175k.mov
Mov file is not directly streamable. So your RTSP source is probably sending you two elementary streams. (I am guessing this is darwin or some other similar server) So you may have to setup two outputs from rtspsrc one for audio and one for video.
rtpmp4vpay is for elementary mpeg4 streams. Is your source file having mpeg4 video codec? If it is h.264 replace it with rtph264depay. you can pass the output to decoder and play it if you want. Feed it to decodebin. To dump it in h.264 you will first have to parse and add nal headers to it ( h264parse parse perhaps? )
rtpmp4gpay is most probably accepted for the audio stream.
I am guessing your file is h.264/aac which is why rtpmp4vdepay wont work and rtpmp4gdepay will. But you are not doing anything about the video when you setup rtpmp4gdepay so you need to do that.
I'm trying to use GDCL MP4 Muxer with my RTSP Source Filter. They work fine together except after stopping the graph, muxer doesn't finilize the file and write the reqiured tables to the end of file via file writer (some parts are written starting from moov but not the time table values). When I try another RTSP source filter (which I don't have its source codes), table values are created with GDCL MP4 Muxer.
But when I try Elecard's MP4 Muxer, it works fine with my RTSP Source Filter. So, there is an incompatibility. I examined GDCL's source codes but couldn't find what it was expecting from me. I already calculate and set timestamp values to samples using SetTime method. But GDCL still doesn't finilaze file. Is it caused by missing information or missing signal when graph stops? What can be the problem, any ideas?
One thing you should be aware of regarding Geraint's MP4 Mux is that it is checking incoming media samples to have both start and stop time. You might be having only .tStart/AM_SAMPLE_TIMEVALID which still makes sense for video, but this would be a problem.
So the samples have to have stop time, or you need to fix this in multiplexer code.
A typical symptom for the problem is that generated files are empty or of zero duration.