timebase

FFmpeg's understanding about Timebase One: FFmpeg's layered structure When writing this article, let's outline the FFmpeg layering problem, which we summarize in accordance with the most common "transcoding program" and "Camera capture" and "player" three models. 1: transcoding transcoding basic Flow: FLV Format Data-->H264/AAC data-->YUV/PCM data-->H264/AAC data-->mp4 format data. A: We call the FLV format data or the MP4 format data This layer is c

", " StrComputer = "." Set objWMIService = GetObject ("winmgmts:" "{impersonationlevel=impersonate}!\\" StrComputer "\root\ Cimv2 ") ' 1th Time sampling Set colitems = objWMIService.ExecQuery ("SELECT * from Win32_perfrawdata_tcpip_networkinterface", 48) Dim BYTESTOTALPERSEC1 (TimeValue1), Name1 (a), Currentbandwidth (a), BYTESRECEIVEDPERSEC1 (20), BYTESSENTPERSEC1 (PACKETSRECEIVEDPERSEC1), PACKETSSENTPERSEC1 (20), _ Bytestotalpersec (Percentnetwork), Bytesreceivedpersec (a), bytessen

timebase;Mach_timebase_info(timebase);return (Double) time * (Double) timebase. Numer/ (double) timebase. denom/1e9; }-(void) profiledosomething// method of detecting code execution time{uint64_t begin = Mach_absolute_time(); Get time with Mach_absolute_time() Here's the iOS code to test,For (int i = 0; i ; i++)

This article illustrates how PHP implements a daily automatic transformation of random greetings. Share to everyone for your reference. The specific analysis is as follows: Here is a predefined PHP array, there are some random greetings, call the time to specify the day, month or year to automatically replace the greeting, if the choice of month, will be a month to replace a greeting show, do not have to manually replace each month, and this section of PHP code than using JS to achieve search e

Php implements the method of automatically changing random greetings every day, and php converts greetings This example describes how php automatically converts random greetings every day. Share it with you for your reference. The specific analysis is as follows: A php array is pre-defined here, which contains some random greetings. You can specify whether the greetings are automatically changed by day, month, or year when calling. If you select month, a new greeting is displayed every month, yo

This article mainly introduces php's method of automatically changing random greetings every day, involving time and array related operations, for more information, see the following example. Share it with you for your reference. The specific analysis is as follows: A php array is pre-defined here, which contains some random greetings. you can specify whether the greetings are automatically changed by day, month, or year when calling. if you select month, a new greeting is displayed every month

scenarios involving the calculation of PTS, it involves the conversion of two time, and exactly where the time_base is taken: Scenario 1: The frame generated by the encoder is deposited directly into the avstream of a container, then the time of packet is converted from Avcodeccontext to the target avstream. Scenario 2: A frame of source Avstream demux out of a container, stored in another container for a purpose avstream. The timescale at this time should be converted from the time of the sou

This article illustrates how PHP implements a daily automatic transformation of random greetings. Share to everyone for your reference. The specific analysis is as follows: Here is a predefined PHP array, there are some random greetings, call the time to specify the day, month or year to automatically replace the greeting, if the choice of month, will be a month to replace a greeting show, do not have to manually replace each month, and this section of PHP code than using JS to achieve search e

This article mainly introduces php's method of automatically changing random greetings every day, involving time and array related operations, for more information, see the following example. Share it with you for your reference. The specific analysis is as follows: A php array is pre-defined here, which contains some random greetings. you can specify whether the greetings are automatically changed by day, month, or year when calling. if you select month, a new greeting is displayed every month

item = netlist [0] As win32_perfrawdata_tcpip_networkinterface; Float countervalue1 = (float) item. bytesreceivedpersec;Float upv1 = (float) item. bytessentpersec;Float timevaluee1 = (float) item. timestamp_perftime;Float timebase = (float) item. frequency_perftime;System. Threading. thread. Sleep (500 ); Netlist. Clear ();Netlist = PNI. selectall ();Item = netlist [0] As win32_perfrawdata_tcpip_networkinterface; Float countervalue2 = (float) i

JMF Brief IntroductionJMF and java media framework. JMF are APIs used to process multimedia resources (audio, video, etc.) in Java. This extension package provides Multimedia Resource playback, transmission, encoding and decoding functions. JMF framework structure: JMF Architecture Time ModelThe time object represents a time point, accurate to one thousandth of a million (nanosecond ). The clock interface defines basic scheduled and synchronous operations to control the performance of multimedia

sampling rate, also has 8k, then this sample rate and num_pkt have what relationship. We found that there is a more important field in Avframe called Nb_samples, this field is named Sample number, this field can be combined with the audio data format to calculate how large this frame->data, In fact, this field combined sample rate can also calculate how many packet the audio has in a second. The calculation formula is as follows: NUM_PKT = sample rate/nb_samples; So we know the number of packet

strictly specified, but is usually named Required Properties:-device_type: Only for "CPU"-reg: The number of physical CPUs, which are typically a 32-bit value, and are used together with the unit name to form the full path of the CPU node. For example, a platform with two CPUs, the full path to the CPU node is as follows:/cpus/powerpc,[email protected]/cpus/powerpc,[email protected]-d-cache-block-size:32 bit value representing L1 data buffer block Size (bytes)-i-cache-block-size:32 bit value in

specific encoder, here is the H264 encoderif (!CODEC) {//Cannot find the target encoder, exitErrorS = 1;Logi ("Codec not found\n");printf ("Codec not found\n");Exit (1);}Cotx = AvcodecAllocCONTEXT3 (codec);??????????????????????? The context is understood as a parameter setting based on the encoder allocation contextif (!cotx) {//Cannot assign context, exitErrorS = 1;Logi ("Could not allocate video codec context\n");printf ("Could not allocate video codec context\n");Exit (1);}Cotx->bitRate = b

[This article is a complex topic of FFMPEG. It will be quite cool to write] [Different transcoding environments may have different code flows] First popularized: Timestamp, DTS (Decoding time stamp), PTS (presention time stamp), CTS (current time stamp ). The timestamp in ffmepg is in microseconds and is related to the timebase variable. It is used as the time benchmark granularity of DTs and PTS, and the value will be large. Among them, the av_resc

common settings for both single conversion and scan mode */Init. timebase = adc_timebasec1c (0 );/* Might as well finish conversion as quickly as possibly since polling *//* For completion .*//* Set ADC clock to 7 MHz, use default HFPERCLK */Init. prescale = adc_prescalec1c (200000, 0 ); /* WARMUPMODE must be set to Normal according to ref manual before *//* Entering EM2. In this example, the warmup time is not a big problem *//* Due to relatively in

([(Slot.id, slot)])Self.wait.update (Box)Return slotdef remove (self, slot):If Isinstance (slot, slot):Self.cancel (slot)TrySelf.wait.pop (slot.id)Except Keyerror:Print "Wait dict not have the cancel timer""" "Timer API" ""def reset (self, slot):If Isinstance (slot, slot):Self.cancel (slot)slot.pc = 0Self.start (slot)def start (self, slot):def Newtimerstamp (Timebase, resolution):nowoffset = Int (Time.time () * +)-timebaseIf Nowoffset% resolution Cur

mainly to adapt the stack/heap size to fit the application requirements. Stm32f4xx_hal_msp.c This file contains the MSP initialization and de-initialization (main routine and callbacks) of the peripheral used in the User application. Stm32f4xx_hal_conf.h This file allows the user to customize the HAL drivers for a specific application. It is not a mandatory to modify this configuration. The application can use the default configuration without any modificat

(real-time code rate change, but average bit rate approaching target bitrate over a period) 1. FPs. The ABR estimates the average amount of data per frame based on the frame rate, bitrate/fps the average one frame of data. When the input video source is YUV data, it is necessary to explicitly specify the correct frame rate--fps, otherwise the X264 will be calculated with the default 25fps, it is possible to control the target bitrate. 2. PTS calculation. The ABR algo

=null; //Format Context int errno=0; Pcontext=avformat_alloc_context (); //Open input File New interface if (0==avformat_open_input (pcontext,". \\test.mp4", Nullptr,null)) { printf ("Open file input succeeded!\n"); }Else return 0; //Retrieve flow information from context if (0==avformat_find_stream_info (pcontext,null)) { printf ("Get flow information successfully!\n"); }Else return 0; //Loop multiple streams SETSTDCLR (foreground_red | Foreground_blue); Fo