h.264

问题 I'm looking for a algorithm of finding reference frames in h264 stream. The most common metod I saw in different solutions was finding access unit delimiters and NAL of IDR type. Unfortunatelly most streams I checked didn't have NAL of IDR type. I'll be gratefull for help. Regards Jacek 回答1: H264 frames split up by a special tag, called the startcode prefix, which is either of 0x00 0x00 0x01 OR 0x00 0x00 0x00 0x01 . All the data between two startcodes comprises a NAL unit in H264 speak. So

问题 I'm looking for a algorithm of finding reference frames in h264 stream. The most common metod I saw in different solutions was finding access unit delimiters and NAL of IDR type. Unfortunatelly most streams I checked didn't have NAL of IDR type. I'll be gratefull for help. Regards Jacek 回答1: H264 frames split up by a special tag, called the startcode prefix, which is either of 0x00 0x00 0x01 OR 0x00 0x00 0x00 0x01 . All the data between two startcodes comprises a NAL unit in H264 speak. So

问题 I would appreciate an example of using the Live555 library to render live streams to screen. Apparently it's simple, but it would really help to see it done rather than simply read that "it's simple"!. The gmane site states: "To update (a copy of) the "testRTSPClient" code so that it renders video data is fairly straightforward: You simply have to change the "DummySink" class, so that it does the rendering (or calls a decoder library to do the rendering). In particular, you would change the

问题 I'm trying to stream live video from my android phone to a desktop RTSP server on my PC. The streamed video can be played in another device. I'm using H.264 video encoder, so the SDP returned by the server (as the reply of DESCRIBE request) should contain the profile-level-id and sprop-parameter-sets fields. The Spydroid project shows how to extract these info from a dummy file recorded to SD card by parsing it (from the avcC block). But I cannot do it like that. In Spydroid, the media

问题 I have an IP Camera which gives H264 annexb Bitstream through SDK calls. I want to pack this video stream into FLV container. So far I've got to know the following :- I have to convert H264 annexb to H264 AVCC : For this I'll have to replace NAL header byte (0x00000001) with Size of NALU (big endian format). My question is, What do I do with SPS and PPS ? should I write (av_interleaved_write_frame) them as are after replacing the NAL header ? or do I not write these frames at all ? I read

问题 I have a program generating a bunch of raw H264 frames and would like to place that into a mp4 container for streaming. Anyone know how to do that? I was thinking I'd use ffmpeg however, this needs to be used commercially and it seems like ffmpeg can only do this through it's x264 library... which uses a GPL license. Thank you! 回答1: libmp4v2 is under the MPL and can be used as part of a larger work commercially. It is much lighter than libavformat also. 回答2: If you're looking for the FFMPEG

问题 I am trying to modify an HLS segment transport stream, and preserve its start time with ffmpeg. However the output does not preserve the input file's start_time value, even if -copyts is mentioned. Here's my command line: ffmpeg -i fileSequence1.ts -i x.png -filter_complex '[0:v][1:v]overlay[out]' -map '[out]' -map 0:1 -acodec copy -vsync 0 -vcodec libx264 -streamid 0:257 -streamid 1:258 -copyts -profile:v baseline -level 3 output.ts The start_time value is delayed about 2 seconds

问题 In a SIP video call, the receiver of the video stream respond with the capabilities of its decoder. The parameter which defines that is the profile-level-id . Here is an example value of the profile-level-id parameter: 428014 RFC 6184 defined that as A base16 [7] (hexadecimal) representation of the following three bytes in the sequence parameter set NAL unit is specified in 1: 1) profile_idc, 2) a byte herein referred to as profile-iop, composed of the values of constraint_set0_flag,

问题 I am looking for a video encoder that is fast, requires less CPU power and produces very good quality mp4 video. The input videos can be in any format and uploaded by users. Only thing I know is FFMPEG library. Is there anything else that is better? The program must have a batch utility (exe) that I am interested in. I would appreciate if you kindly share your knowledge. Thanks 回答1: Use x264 . It's fast and flexible enough for it to suit your needs. Other H.264 video encoders are junk

问题 I am working on a h264 video codec. I want to know: Is a single NAL unit in H264 equivalent to one video frame? 回答1: No, a sequence of NAL units can be decoded into video frames, but they are not equivalent. http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC http://en.wikipedia.org/wiki/Network_Abstraction_Layer#NAL_Units_in_Byte-Stream_Format_Use http://wiki.multimedia.cx/index.php?title=H.264 来源： https://stackoverflow.com/questions/6858991/in-h264-nal-units-means-frame