Newest 'libx264' Questions - Stack Overflow

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  • How to reduce the quality of H264 Video

    20 février 2014, par user3239282

    How to reduce the quality of H264 video using libx264 library, for transmission over internet.

    I want to reduce the quality, so that the frame size will become small and decreases the network latency while transferring over internet.

  • Reduce Bandwidth requirement for Video Streaming

    19 février 2014, par user3239282

    Please suggest some points on, how to reduce the bandwidth requirement for a video stream.

    We are actually streaming the desktop across internet, Remote Access Application.

    Encoder : libx264.lib

    Decoder : Ffmpeg

    Codec : H264

    Following is how am configuring h264 for encoding:

        x264_param_default_preset(&this->m_x264Settings, "veryfast", "zerolatency");
    this->m_x264Settings.i_threads = 1;
    this->m_x264Settings.i_width = width / 2;
    this->m_x264Settings.i_height = height / 2;
    this->m_x264Settings.i_keyint_max = 10;//fps;
    this->m_x264Settings.b_intra_refresh = 1;
    this->m_x264Settings.i_fps_num = 10;
    this->m_x264Settings.i_fps_den = 1;
    // Intra refres:
    this->m_x264Settings.i_keyint_max = 25;
    this->m_x264Settings.b_intra_refresh = 1;
    //Rate control:
    this->m_x264Settings.rc.i_rc_method = X264_RC_CRF;
    this->m_x264Settings.rc.f_rf_constant = 25;
    this->m_x264Settings.rc.f_rf_constant_max = 35;

    //For streaming:
    this->m_x264Settings.b_repeat_headers = 1;
    this->m_x264Settings.b_annexb = 1;
    x264_param_apply_profile(&this->m_x264Settings, "baseline");

    this->m_width = width;
    this->m_height = height;
    this->m_encoder = x264_encoder_open(&this->m_x264Settings);
    x264_picture_alloc(&this->m_picIn,X264_CSP_I420,(width / 2),(height / 2));
    int sws_flags = SWS_BICUBIC;
    m_imgConverCtx = sws_getContext(width, height, PIX_FMT_RGB32, (width/2), (height/2), PIX_FMT_YUV420P,sws_flags, NULL, NULL, NULL);

    Thanks in advance, Paul.

  • Android link many static libraries into shared library

    3 février 2014, par nmxprime

    i have 4 static libraries libavcodec.a libavutil.a libswscale.a libx264.a

    I want to link it with libmytest.so

    I tried below Android.mk script

    LOCAL_PATH := $(call my-dir)
INITIAL_PATH := $(LOCAL_PATH)

include $(CLEAR_VARS)
LOCAL_MODULE := mytest

LOCAL_SRC_FILES := mytest.c

LOCAL_LDLIBS += -llog
LOCAL_WHOLE_STATIC_LIBRARIES := libavutil libavcodec libswscale libx264

include $(BUILD_SHARED_LIBRARY)

    mytest.c calls many functions from those libraries. The 4 libraries are placed inside PROJECTPATH\jni\.

    But i get undefined reference to all functions from those libraries.

    I tried giving LOCAL_ALLOW_UNDEFINED_SYMBOLS := truewhich allowed me to create shared library, but when i launch the app, i get 

    01-22 07:15:15.650: E/AndroidRuntime(9655): Caused by: java.lang.UnsatisfiedLinkError: Cannot load library: reloc_library[1285]:  1868 cannot locate 'avcodec_register_all'...
01-22 07:15:15.650: E/AndroidRuntime(9655):     at java.lang.Runtime.loadLibrary(Runtime.java:370)
01-22 07:15:15.650: E/AndroidRuntime(9655):     at java.lang.System.loadLibrary(System.java:535)

  • Building ffmpeg for ubuntu No working C compiler found

    27 janvier 2014, par Whoami

    I am building ffmpeg on ubuntu. I could able to build yasm-1.2.0, and next i tried building x264. x264 requires minumum of yasm-1.2.0, Hence i tried the below command to build x264.

    ./configure --prefix= --bindir= --extracflgs= --extra-ldflags=

    I got the below error:

    No working C compiler found.

    Not sure what error i commited. Could someone kindly tell me what do i have to do?

  • ffmpeg libx264 neon optimization breaks execution

    27 janvier 2014, par nmxprime

    Hi use libx264 source obtained from x264-snapshot-20140122-2245 and compiling using below script

    NDK=~/Android/android-ndk-r7c
PLATFORM=$NDK/platforms/android-9/arch-arm/
PREBUILT=$NDK/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86
function build_one
{
./configure --prefix=$PREFIX \
--sysroot=$PLATFORM \
--disable-avs \
--disable-lavf \
--disable-ffms \
--disable-gpac \
--cross-prefix=$PREBUILT/bin/arm-linux-androideabi- \
--host=arm-linux \
--enable-static \
--libdir=$PLATFORM/usr/lib \
--includedir=$PLATFORM/usr/include \
--extra-cflags="-march=armv7-a -mfloat-abi=softfp -mfpu=neon -mvectorize-with-neon-quad" \
--extra-ldflags="-Wl,--fix-cortex-a8" \
--enable-debug

    The config log is: 

    platform:      ARM
system:        LINUX
cli:           yes
libx264:       internal
shared:        no
static:        yes
asm:           yes
interlaced:    yes
avs:           no
lavf:          no
ffms:          no
mp4:           no
gpl:           yes
thread:        no
opencl:        yes
filters:       crop select_every
debug:         yes
gprof:         no
strip:         no
PIC:           no
bit depth:     8
chroma format: all

You can run 'make' or 'make fprofiled' now.

    I hope the above code compiles and optimizes for NEON execution

    Doubts:

    Why Threads is no, because i didn't specified --disable-thread

    What is cli and it's significance here, also significance of opencl, such that libx264 uses opencl features?

    Then i built ffmpeg 1.2.5with following script

    ./configure --target-os=linux \
--prefix=$PREFIX \
--enable-cross-compile \
--extra-libs="-lgcc" \
--arch=arm \
--cc=$PREBUILT/bin/arm-linux-androideabi-gcc \
--cross-prefix=$PREBUILT/bin/arm-linux-androideabi- \
--nm=$PREBUILT/bin/arm-linux-androideabi-nm \
--sysroot=$PLATFORM \
--extra-cflags=" -O3 -fpic -DANDROID -DHAVE_SYS_UIO_H=1 -Dipv6mr_interface=ipv6mr_ifindex -fasm -Wno-psabi -fno-short-enums -fno-strict-aliasing -finline-limit=300 $OPTIMIZE_CFLAGS " \
--disable-shared \
--enable-static \
--extra-ldflags="-Wl,-rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib -nostdlib -lc -lm -ldl -llog -lx264 $EXTRA_LD_FLAG" \
--disable-ffplay \
--disable-everything \
--enable-avformat \
--enable-avcodec \
--enable-libx264 \
--enable-gpl \
--enable-encoder=libx264 \
--enable-encoder=libx264rgb \
--enable-decoder=h264 \
--disable-network \
--disable-avfilter \
--disable-avdevice \
--enable-debug=3 \
$ADDITIONAL_CONFIGURE_FLAG

    where 

    ADDITIONAL_CONFIGURE_FLAG = --enable-debug=3
OPTIMIZE_CFLAGS="-mfloat-abi=softfp -mfpu=neon -marm -march=$CPU -mvectorize-with-neon-quad"

    The log shows NEON supported.

    When i run the code (called in a while loop), 

    ret = avcodec_encode_video2(c, &pkt, picture, &got_output);//avcodec_encode_video(c, finalout, outbuf_size, picture);

fprintf(stderr,"ret = %d, got-out = %d \n",ret,got_output);
if (ret < 0) 
        fprintf(stderr, "error encoding frame\n");

    if (got_output) 
        fprintf(stderr,"encoding frame %3d (size=%5d): (ret=%d)\n", 1, pkt.size,ret);

    it runs for 2 or 3 time(during which if(got_output) is not true), then i get SIGSEGV. Tried addr2line and ndk-stack but no use[Though i enabled debug info, ndk-stack cannot find routine info].

    I edited libx264's encoder.c code with some fprintf statements. Posting snippet of code

       if( h->frames.i_input <= h->frames.i_delay + 1 - h->i_thread_frames )
    {
        /* Nothing yet to encode, waiting for filling of buffers */
        pic_out->i_type = X264_TYPE_AUTO;
fprintf(stderr,"EditLog:: Returns as waiting for filling \n"); //edit
        return 0;
    }
}

else
{
    /* signal kills for lookahead thread */
    x264_pthread_mutex_lock( &h->lookahead->ifbuf.mutex );
    h->lookahead->b_exit_thread = 1;
    x264_pthread_cond_broadcast( &h->lookahead->ifbuf.cv_fill );
    x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
}
fprintf(stderr,"After wait for fill \n");
fprintf(stderr,"h: %p \n",h); //edit
fprintf(stderr,"h->i_frame = %p \n",&h->i_frame); //edit
h->i_frame++;
fprintf(stderr,"after i_frame++");

    in log, i don't see after i_frame++, here occurs (may be) the SIGSEGV.

    Please help in solving it. The same works without neon optimization!!

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