h.264

问题 What is the meaning of Base64 decoded bytes in sprop-parameter-sets in SDP for a h264 stream? How can I know the video size from this example? SDP example: sprop-parameter-sets=Z0IAKeNQFAe2AtwEBAaQeJEV,aM48gA== First part decoded from Base64 to Base16: 67 42 00 29 E3 50 14 07 B6 02 DC 04 04 06 90 78 91 15 Second part (comma separated): 68 CE 3C 80 ANSWER: Fetching the dimensions of a H264Video stream 回答1: The spec you require is available for free download from the ITU website here:- H.264

问题 What is the meaning of Base64 decoded bytes in sprop-parameter-sets in SDP for a h264 stream? How can I know the video size from this example? SDP example: sprop-parameter-sets=Z0IAKeNQFAe2AtwEBAaQeJEV,aM48gA== First part decoded from Base64 to Base16: 67 42 00 29 E3 50 14 07 B6 02 DC 04 04 06 90 78 91 15 Second part (comma separated): 68 CE 3C 80 ANSWER: Fetching the dimensions of a H264Video stream 回答1: The spec you require is available for free download from the ITU website here:- H.264

问题 I am trying to mux H.264 data into a MP4 file. There appear to be no errors in saving this H.264 Annex B data out to an MP4 file, but the file fails to playback. I've done a binary comparison on the files and the issue seems to be somewhere in what is being written to the footer (trailer) of the MP4 file. I suspect it has to be something with the way the stream is being created or something. Init: AVOutputFormat* fmt = av_guess_format( 0, "out.mp4", 0 ); oc = avformat_alloc_context(); oc-

问题 I'm capturing the desktop using DesktopDuplication API and converting the samples from RGBA to NV12 in GPU and feeding the same to MediaFoundation hardware H264 MFT. This works fine with Nvidia graphics, and also with software encoders but fails when only intel graphics hardware MFT is available. The code works fine on the same intel graphics machine if I fallback to Software MFT. I also have ensured that the encoding is actually done in hardware on Nvidia graphics machines. On Intel graphics

问题 I'm trying to stream the desktop(DirectX surface in NV12 format) as H264 video over RTP stream using Live555 & Windows media foundation's hardware encoder on Windows10, and expecting it to be rendered by ffplay (ffmpeg 4.2). But only getting a green screen like below, I referred MFWebCamToRTP mediafoundation-sample & Encoding DirectX surface using hardware MFT for implementing live555's FramedSource and changing the input source to DirectX surface instead of webCam. Here is an excerpt of my

问题 I have a card that produces a H264 stream with a SPS (Sequence Parameter Set) and a PPS (Picture Parameter Set), in that order, directly before each I-Frame. I see that most H264 streams contain a PPS and SPS at the first I-Frame. Is this recommended? Do decoders/muxers typically support multiple PPS and SRS? 回答1: H.264 comes in a variety of stream formats. One variation is called "Annex B". (AUD)(SPS)(PPS)(I-Slice)(PPS)(P-Slice)(PPS)(P-Slice) ... (AUD)(SPS)(PPS)(I-Slice). Typically you see

问题 Is it possible to do completely lossless encoding in h264? By lossless, I mean that if I feed it a series of frames and encode them, and then if I extract all the frames from the encoded video, I will get the exact same frames as in the input, pixel by pixel, frame by frame. Is that actually possible? Take this example: I generate a bunch of frames, then I encode the image sequence to an uncompressed AVI (with something like virtualdub), I then apply lossless h264 (the help files claim that

问题 Is it possible to do completely lossless encoding in h264? By lossless, I mean that if I feed it a series of frames and encode them, and then if I extract all the frames from the encoded video, I will get the exact same frames as in the input, pixel by pixel, frame by frame. Is that actually possible? Take this example: I generate a bunch of frames, then I encode the image sequence to an uncompressed AVI (with something like virtualdub), I then apply lossless h264 (the help files claim that

问题 I performed some simple timing of MoviePlayer.java in the Grafika MediaCodec sample code running on a Nexus 5. I put a log statement at these locations: At line 203 just before decoder.queueInputBuffer At line 244 after decoder.dequeueOutputBuffer I correlated the log statements using presentationTimeUs . Here is an excerpt from logcat: 01-29 10:56:43.295: I/Grafika(21286): queueInputBuffer index/pts, 2,0 01-29 10:56:43.305: I/Grafika(21286): queueInputBuffer index/pts, 0,33100 01-29 10:56:43

问题 I'm trying to get this to work on Android 4.1 (using an upgraded Asus Transformer tablet). Thanks to Alex's response to my previous question, I already was able to write some raw H.264 data to a file, but this file is only playable with ffplay -f h264 , and it seems like it's lost all information regarding the framerate (extremely fast playback). Also the color-space looks incorrect (atm using the camera's default on encoder's side). public class AvcEncoder { private MediaCodec mediaCodec;