bitrate

FFMPEG: Dynamic change of bit_rate for Video

由 两盒软妹~` 提交于 2019-12-13 15:25:43
问题 I use ffmpeg codes in my C++ app and would like to control the bit_rate parameter for VIDEO there. I tried to change its value in work (via ost->st->codec->codec->bit_rate), but ffmpeg did not wish to change it. Perhaps anybody knows how to make it? Any ideas? 回答1: I have tried like this and its working for me. avcodec_init(); avcodec_register_all(); codec = avcodec_find_encoder(CODEC_ID_H263); c = avcodec_alloc_context(); picture= avcodec_alloc_frame(); c->bit_rate = bitrate; c->width = w; c

Is “Bit rate” property fixed in index 28?

由 泪湿孤枕 提交于 2019-12-13 14:24:15
问题 I am trying to read "Bit rate" property of audio files. I know how to get the value but the way I am doing it I don't think is the most efficient. Shell shell = new Shell32.Shell(); Folder objFolder = shell.NameSpace(path); for (int i = 0; i < short.MaxValue; i++) { string property = objFolder.GetDetailsOf(null, i); if (String.IsNullOrEmpty(property)) break; if (property.Equals("Bit rate")) { index = i; break; } } FolderItem item = objFolder.ParseName(fileName); string bitRateValue =

How to specify encoding bitrate while capturing from a webcam - MS Expression Encoder 4

由 假装没事ソ 提交于 2019-12-13 02:07:36
问题 I have a program to capture and save live webcam video. This is taken from sample programs coming with Expression Encoder 4. LiveJob job = new LiveJob(); EncoderDevice video = EncoderDevices.FindDevices(EncoderDeviceType.Video).Count > 0 ? EncoderDevices.FindDevices(EncoderDeviceType.Video)[0] : null; EncoderDevice audio = EncoderDevices.FindDevices(EncoderDeviceType.Audio).Count > 0 ? EncoderDevices.FindDevices(EncoderDeviceType.Audio)[0] : null; LiveDeviceSource deviceSource = job

How to amplify, increase bitrate and Fadin- fadout the recorded audio in Windows Phone 7?

由 旧城冷巷雨未停 提交于 2019-12-12 05:16:31
问题 I am facing the following problem regarding to the voice (Audio) recording in windows phone 7. I am recording the sound using Microphone class available in Microsoft.Xna.Framework.Audio namespace. here is the code - Variable declaration: private Microphone mic = Microphone.Default; private MemoryStream stream; private const string FILE_NAME = "recording.mp3"; byte[] buffer; Recording Button click code- mic.BufferDuration = TimeSpan.FromSeconds(1); buffer = new byte[mic.GetSampleSizeInBytes

Why bandwidth is measured in bits per second?

由 自作多情 提交于 2019-12-11 11:33:26
问题 According to the definition of the bandwidth, it is the width of the frequency spectrum. Hence bandwidth should be measured in Hz. But bps, Mbps, kbps have been used as the measurement of bandwidth almost everywhere. What I need to know is, why bps, kbps kind of measurements of data transmission rate are used to measure the bandwidth of a signal. 回答1: Throughput, measured in bps, Mbps, Kbps, is mistakenly referred to as bandwidth because of a mis-conception of the Shannon-Hartley law. The

FFmpeg: bitrate change dynamically

由 怎甘沉沦 提交于 2019-12-11 08:23:03
问题 I read the previous thread and this is the response from NISHAnT, FFMPEG: Dynamic change of bit_rate for Video avcodec_init(); avcodec_register_all(); codec = avcodec_find_encoder(CODEC_ID_H263); c = avcodec_alloc_context(); picture= avcodec_alloc_frame(); c->bit_rate = bitrate; c->width = w; c->height = h; c->time_base= (AVRational){1,framerate}; c->pix_fmt = PIX_FMT_YUV420P; avcodec_close(c); av_free(c); And this is my code: if(previous_BR != cur_BR){ previous_BR = cur_BR; AVCodecContext*

How to get an MP3 bit rate in SWIFT

由 ∥☆過路亽．° 提交于 2019-12-10 23:08:47
问题 I am searching for a way of getting an mp3 bitrate like 128kbps or 320kbps for mp3 audio from url link. I have a UITableView that loads a list of files from url list, and I would like to display an audio quality. I have tried using AVAudioPlayer and AVPlayer but no luck. Please help, how can I achieve this? do{ let audioPlayer = try AVAudioPlayer(contentsOf:audioURL) print(audioPlayer.settings) if #available(iOS 10.0, *) { print(audioPlayer.format) } else { // Fallback on earlier versions }

Bitrate JWplayer

由 北慕城南 提交于 2019-12-08 03:35:00
问题 I am having trouble to make jwplayer work with different bitrates. For each video, I am creating new output files with different suffixes that have lower bitrates: For instance, Output 1 (high bitrate): test-original.mp4 Output 2 (medium bitrate): test-medium.mp4 Output 2 (low bitrate): test-low.mp4 The output file names are dynamic as the users can upload as many different video files as they want. jwplayer configuration: jwplayer('video-container').setup({ 'sources':[ {'file': "rtmps://" +

Difference between sampling rate, bit rate and bit depth

由 我与影子孤独终老i 提交于 2019-12-08 02:16:49
问题 This is kind of a basic question which might sound too obvious to many of you , but I am getting confused so bad. Here is what a Quora user says. Now It is clear to me what a Sampling rate is - The number of samples you take of a sound signal (in one second) is it's sampling rate. Now my doubt here is - This rate should have nothing to do with the quantisation , right? About bit-depth , Is the quantisation dependant on bit-depth? As in 32-bit (2^32 levels) and 64-bit (2^64 levels). Or is it

Ffmpeg creating m3u8 from mp4, video file size

由 ぃ、小莉子 提交于 2019-12-04 17:13:12
I am using ffmpeg to convert mp4 to m3u8. But first I need to make mp4 smaller. I use this code to make it smaller: ffmpeg -i big.mp4 -b 1000000 small.mp4 Then I use this code to convert it to m3u8 ffmpeg -i small.mp4 -g 60 -hls_time 2 -hls_list_size 0 -hls_segment_size 500000 output.m3u8 Is there a way to do this in once? Just combine them: ffmpeg -i big.mp4 -b:v 1M -g 60 -hls_time 2 -hls_list_size 0 -hls_segment_size 500000 output.m3u8 Note that you're transcoding the video twice in your current workflow. Since the 2nd command hasn't set video codec option to copy, it gets transcoded again -
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