x264

Build FFMPEG with x264 for Android

由 情到浓时终转凉″ 提交于 2019-12-18 12:23:08
问题 I am trying to build FFMPEG with libx264 for Android. I can successfully build and use FFMPEG for Android but I realized that I need the ability to encode, therefore I am trying to build FFMPEG with x264. I am using this tutorial to build FFmpeg for Android http://www.roman10.net/how-to-build-ffmpeg-for-android/ When trying to build FFMPEG I get an error: "ERROR: libx264 not found" And in my log it says: "/usr/local/lib/libx264.a: could not read symbols: Archive has no index; run ranlib to

How to encode a video from several images generated in a C++ program without writing the separate frame images to disk?

由 馋奶兔 提交于 2019-12-17 22:08:32
问题 I am writing a C++ code where a sequence of N different frames is generated after performing some operations implemented therein. After each frame is completed, I write it on the disk as IMG_%d.png, and finally I encode them to a video through ffmpeg using the x264 codec. The summarized pseudocode of the main part of the program is the following one: std::vector<int> B(width*height*3); for (i=0; i<N; i++) { // void generateframe(std::vector<int> &, int) generateframe(B, i); // Returns

h264 lossless coding

由 点点圈 提交于 2019-12-17 08:33:59
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

h264 lossless coding

由 喜你入骨 提交于 2019-12-17 08:32:27
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

x264中的decimate_score

由 孤街浪徒 提交于 2019-12-16 22:28:19
为了减少残差系数使用的编码比特，x264中使用了一种方法--decimation。原话是这样子的： Writing the 16 CBFs in an i16x16 block is quite costly, so decimation can save many bits. More useful with CAVLC, but still useful with CABAC. 中心思想是如果一个16x16块的非零残差系数个数很少且最大绝对值不超过1（用一个score来衡量），直接将其所有4x4块的残差系数置为0，这样子就不要为该16x16块发送16个cbf； 对于亮度，如果是8x8块，则score<4时，将残差系数全置为0； 如果是16x16块，则score<6时，将残差系数全置为0； 对于色度， 则score<7时，将残差系数全置为0； 该技术一般用于帧间宏块，总共在下面几个函数应用： x264_mb_encode_i16x16； x264_macroblock_encode_p8x8_internal； x264_macroblock_probe_skip_internal； x264_macroblock_encode_internal； x264_mb_encode_chroma_internal； 以x264_mb_encode_i16x16为例来看看：

x264编码器设置

由 好久不见. 提交于 2019-12-16 02:56:00
1、 JNIEXPORT void JNICALL Java_com_dongnaoedu_live_jni_PushNative_setVideoOptions (JNIEnv *env, jobject jobj, jint width, jint height, jint bitrate, jint fps){ x264_param_t param; //x264_param_default_preset 设置 x264_param_default_preset(&param,"ultrafast","zerolatency"); //编码输入的像素格式YUV420P param.i_csp = X264_CSP_I420; param.i_width = width; param.i_height = height; y_len = width * height; u_len = y_len / 4; v_len = u_len; //参数i_rc_method表示码率控制，CQP(恒定质量)，CRF(恒定码率)，ABR(平均码率) //恒定码率，会尽量控制在固定码率 param.rc.i_rc_method = X264_RC_CRF; param.rc.i_bitrate = bitrate / 1000; //* 码率(比特率,单位Kbps) param.rc.i

【FFMPEG】x264 命令行去除B帧

由 ♀尐吖头ヾ 提交于 2019-12-15 03:54:50
三种方法 此去除B帧的方法只适用于采用 libx264 编码器编码的视频 引用链接： ffmpeg x264 选项指南 第一种 参数中加 -bf 0 ffmpeg -i test.mp4 -vcodec libx264 -bf 0 test-640x480.h264 第二种 参数中加 -x264opts "bframe=0" ffmpeg -i test.mp4 -vcodec libx264 -x264opts "bframes=0" test-640x480.h264 第三种 参数中加 -profile:v baseline ffmpeg -i test.mp4 -vcodec libx264 -profile:v baseline -pix_fmt yuv420p -s 640x480 -acodec aac test1.mp4 加这个参数时，请指定图像格式，否则很容易报错 No pixel format specified, yuv444p for H.264 encoding chosen. Use -pix_fmt yuv420p for compatibility with outdated media players. x264 [error]: main profile doesn't support 4:4:4 [libx264 @ 0x8fa9640]

GOP size for realtime video stream

由 ◇◆丶佛笑我妖孽 提交于 2019-12-13 16:49:29
问题 I'm working on a kind of rich remote desktop system, with a video stream of the desktop encoded using avcodec/x264. I have to set manually the GOP size for the stream, and so far I was using a size of fps/2. But I've just read the following on Wikipedia: This structure [Group Of Picture@ suggests a problem because the fourth frame (a P-frame) is needed in order to predict the second and the third (B-frames). So we need to transmit the P-frame before the B-frames and it will delay the

FFmpeg installation for x264 codec

由 蓝咒 提交于 2019-12-13 02:41:05
问题 can anybody help me out in where can i find ffmpeg download for windows x264 codec , am developing a website which converts any file format to mp4h264 baseline format , everythng was fine with another wrap installer called MooO ffmpeg which i found in this link http://www.moo0.com/?top=http://www.moo0.com/software/FFmpeg/ evrythng is fine i can access the exe from my local system as the file is installed rather i could acess the same when its in remote as i knw the batch file location is

FFmpeg cannot recognize a preset even though it does exist Ubuntu 12.04

由 六眼飞鱼酱① 提交于 2019-12-12 16:10:14
问题 I have installed ffmpeg and x264 folloowing the steps in this documentation :http://ffmpeg.org/trac/ffmpeg/wiki/UbuntuCompilationGuide Now I have this line to execute : sudo /usr/bin/ffmpeg -i input_file.flv -f flv -vcodec libx264 -vpre normal -r 25 -s 0x0 -aspect 1.7777777777778 -padcolor 000000 -padtop 0 -padbottom 0 -padleft 0 -padright 0 -acodec libfaac -ab 128000 -ar 22050 output_file.flv Input #0, flv, from 'WIN! Jwow.flv': Metadata: starttime : 0 totalduration : 101 totaldatarate : 865
订阅 x264