GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together. If nothing happens, download GitHub Desktop and try again.
If nothing happens, download Xcode and try again. If nothing happens, download the GitHub extension for Visual Studio and try again. I wanted to use the Raspberry Pi camera to encode video for HLS streaming, the format used by iPhones, iPads and many other kinds of device. Unfortunately I couldn't easily discover how to modify raspivid to produce videos in the precise format required for HLS.
I expect that it's possible and that I didn't look hard enough. Each unit has a type a unit is similar to a packet: just a chunk of data with a header ; many contain compressed video data but two, SPS and PPS contain parameters about the dimensions of the video amongst other things that are needed to decode it properly.
The reason for that is that we're next going to pass the stream to ffmpeg to be split into chunks a few seconds long and it can only split the stream at a key frame.
At the time of writing that's been successfully streaming live video from my Raspberry Pi camera for quite a few hours. And the quality is astonishing for such a small camera. I'll link to some once it's daylight again and I have something worth sharing.
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Video Production Stack Exchange is a question and answer site for engineers, producers, editors, and enthusiasts spanning the fields of video, and media creation. It only takes a minute to sign up. Does raw H data stripped from an RTP stream contain information about the framerate? Or is the framerate derived either from RTP timestamps for stream reproduction or written the container files avi, mkv RTP is just a protocol for data transfer, it doesn't contain any specific information about the internals of the data transmitted.
The information should be contained in the. Sign up to join this community. The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. H framerate information? Ask Question. Asked 5 years, 10 months ago.
Active 1 month ago. Viewed 9k times. Active Oldest Votes. The motivation for the question was reading somewhere on the web can't locate the references that the playback of raw h data requires a value for the frame rate to be specified.
Like it says in the article, the framerate can somtimes not be present in the SPS. I do not know the reason for that but in that case you will have to specify the framerate. Sign up or log in Sign up using Google.
Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog.Search everywhere only in this topic. Advanced Search. Classic List Threaded. I got H. Thanks in advance.
Luca Abeni. Or maybe the extradata are malformed it happens when reading the H. Maybe this can be fixed by using a proper bitstream filter. Can you have a look at the SDP, and check the sprop-parameter-sets attribute? Also, how are you encoding the h video? You are right - I used this flag as it was mentioned in the OutputExample. What are the benefits of using out-band, compared to in-band - does it means less bandwidth required?
I'm encoding the h. Now the H. The new problem now that H. QuickTime player simply trying to connect to the stream, without any success.
It only takes a minute to sign up. After looking for a while I understand some intermediary frame might be missing. However, using the -g option this way does not change anything:. It is a problem for me because I am using the raspberry as a securiy camera.
My desktop can be restarted from time to time and I need ffplay to be able to catch after the streaming is started. It turns out it is impossible to live stream with the RPi hardware acceleration using ffmpeg. Raspivid and gstreamer does that though. So turn to thoses solution and forget about ffmpeg. Sign up to join this community.
waiting for SPS/PPS when sending H.264 via RTP
The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. Asked 3 years, 1 month ago. Active 4 months ago. Viewed 3k times. Trying to stream a webcam through rtp with a raspberry pi. Cating the SDP file on my desktop, and launching ffplay: ffplay sdp. Any help is appreciated. Luke Skywalker. Luke Skywalker Luke Skywalker 1 1 silver badge 6 6 bronze badges.
Rather than a intermediary frame being missing, it's about head frames. When ffplay starts, if the first frame it receives is not a keyframe, then that frame needs a previous missing frame to get decoded.
That previous frame may be a I-frame not queued to be ever shown or a P frame referred to by a B-frame and would have been shown after the B-frame had it been received. I'm confused. Does it mean there is no solution to this problem it's the way rdp works, the listener has to be started and then the flow started or there would be a way to regularly insert a keyframe for the listener to be able to catch the stream in the middle.
Does the stream not become smooth after a few seconds? No, ffplay keeps outputing error message for ever. It is never able to display any frame. Active Oldest Votes. If this is the issue, then you may be able to stream the omx encode to a pipe in mpegts format and then use a 2nd ffmpeg instance to pipe to rtp.
Serveurperso Serveurperso 1 1 1 bronze badge. Consider submitting a patch to ffmpeg-devel but make it an option instead of hardcoded.The intent of the H. This was achieved with features such as a reduced-complexity integer discrete cosine transform integer DCT   variable block-size segmentation, and multi-picture inter-picture prediction.
The H. A specific decoder decodes at least one, but not necessarily all profiles. The final drafting work on the first version of the standard was completed in Mayand various extensions of its capabilities have been added in subsequent editions. A license covering most but not all patents essential to H. The commercial use of patented H. It is thus common to refer to the standard with names such as H.Makito X HEVC and H.264 Video Encoder
Such partnership and multiple naming is not uncommon. The first draft design for that new standard was adopted in August That work included the development of two new profiles of the standard: the Multiview High Profile and the Stereo High Profile. Throughout the development of the standard, additional messages for containing supplemental enhancement information SEI have been developed.
SEI messages can contain various types of data that indicate the timing of the video pictures or describe various properties of the coded video or how it can be used or enhanced. SEI messages are also defined that can contain arbitrary user-defined data. SEI messages do not affect the core decoding process, but can indicate how the video is recommended to be post-processed or displayed. Some other high-level properties of the video content are conveyed in video usability information VUIsuch as the indication of the color space for interpretation of the video content.
As new color spaces have been developed, such as for high dynamic range and wide color gamut video, additional VUI identifiers have been added to indicate them. The standardization of the first version of H. YUV and The design work on the FRExt project was completed in Julyand the drafting work on them was completed in September Five other new profiles see version 7 below intended primarily for professional applications were then developed, adding extended-gamut color space support, defining additional aspect ratio indicators, defining two additional types of "supplemental enhancement information" post-filter hint and tone mappingand deprecating one of the prior FRExt profiles the High profile that industry feedback [ by whom?
h264 sps pps详解
Specified in Annex G of H. For temporal bitstream scalability i. In this case, high-level syntax and inter-prediction reference pictures in the bitstream are constructed accordingly. On the other hand, for spatial and quality bitstream scalability i.
In this case, inter-layer prediction i. The Scalable Video Coding extensions were completed in November Specified in Annex H of H. An important example of this functionality is stereoscopic 3D video coding. Two profiles were developed in the MVC work: Multiview High profile supports an arbitrary number of views, and Stereo High profile is designed specifically for two-view stereoscopic video.
The Multiview Video Coding extensions were completed in November Additional extensions were later developed that included 3D video coding with joint coding of depth maps and texture termed 3D-AVCmulti-resolution frame-compatible MFC stereoscopic and 3D-MFC coding, various additional combinations of features, and higher frame sizes and frame rates. Versions of the H. Each version represents changes relative to the next lower version that is integrated into the text.
With the use of H.The main difference between these media types is the presence of start codes in the bitstream. According to this specification, the bitstream consists of a sequence of network abstraction layer units NALUseach of which is prefixed with a start code equal to 0x or 0x When the bitstream contains start codes, any of the format types listed here is sufficient, because the decoder does not require any additional information to parse the stream.
The bitstream already contains all of the information needed by the decoder, and the start codes enable the decoder to locate the start of each NALU. The MP4 container format stores H. The size of the length field can vary, but is typically 1, 2, or 4 bytes. This structure should be filled in as follows:. This enables the decoder to recover from data corruption or dropped samples. Skip to main content. Exit focus mode. These subtype GUIDs are declared in wmcodecdsp.
The following subtypes are equivalent: H. When start codes are not present in the bitstream, the following media type is used.
Set to zero. The length field indicates the size of the following NALU in bytes. The valid values are 1, 2, and 4. Related Articles Is this page helpful? Yes No. Any additional feedback? Skip Submit.
Is this page helpful?Discover the new easier way to develop Kurento video applications. Some of the most important types of NAL units are:. Both PPS and SPS can be sent well ahead of the actual units that will refer to them; then, each individual unit will just contain an index pointing to the corresponding parameter set, so the receiver is able to successfully decode the video.
Parameter sets can be sent in-band with the actual video, or sent out-of-band via some channel which might be more reliable than the transport of the video itself. This second option makes sense for transports where it is possible that some corruption or information loss might happen; losing a PPS could prevent decoding of a whole frame, and losing an SPS would be worse as it could render a whole chunk of the video impossible to decode, so it is important to transmit these parameter sets via the most reliable channel.
This describes in detail all aspects of the encoded video; some of them are universal properties of any video such as the width, height and frameratewhile others are highly specific to the H. MPEG-4 as follows:. Kurento 6. The NAL units are delivered as a continuous stream of bytes, which means that some boundary mechanism will be needed for the receiver to detect when one unit ends and the next one starts. This is done with the typical method of adding a unique byte pattern before each unit: The receiver will scan the incoming stream, searching for this 3-byte start code prefixand finding one will mark the beginning of a new unit.
For packet-oriented transports: the Packet-Transport Format. Read the Docs v: 6.