Recherche avancée

Sur d’autres sites (7573)

• aarch64 : vp9 : Implement NEON loop filters

  13 novembre 2016, par Martin Storsjö

  aarch64 : vp9 : Implement NEON loop filters
  This work is sponsored by, and copyright, Google.
  These are ported from the ARM version ; thanks to the larger
  
  amount of registers available, we can do the loop filters with
  
  16 pixels at a time. The implementation is fully templated, with
  
  a single macro which can generate versions for both 8 and
  
  16 pixels wide, for both 4, 8 and 16 pixels loop filters
  
  (and the 4/8 mixed versions as well).
  For the 8 pixel wide versions, it is pretty close in speed (the
  
  v_4_8 and v_8_8 filters are the best examples of this ; the h_4_8
  
  and h_8_8 filters seem to get some gain in the load/transpose/store
  
  part). For the 16 pixels wide ones, we get a speedup of around
  
  1.2-1.4x compared to the 32 bit version.
  Examples of runtimes vs the 32 bit version, on a Cortex A53 :
  
                                         ARM AArch64
  
  vp9_loop_filter_h_4_8_neon :          144.0   127.2
  
  vp9_loop_filter_h_8_8_neon :          207.0   182.5
  
  vp9_loop_filter_h_16_8_neon :         415.0   328.7
  
  vp9_loop_filter_h_16_16_neon :        672.0   558.6
  
  vp9_loop_filter_mix2_h_44_16_neon :   302.0   203.5
  
  vp9_loop_filter_mix2_h_48_16_neon :   365.0   305.2
  
  vp9_loop_filter_mix2_h_84_16_neon :   365.0   305.2
  
  vp9_loop_filter_mix2_h_88_16_neon :   376.0   305.2
  
  vp9_loop_filter_mix2_v_44_16_neon :   193.2   128.2
  
  vp9_loop_filter_mix2_v_48_16_neon :   246.7   218.4
  
  vp9_loop_filter_mix2_v_84_16_neon :   248.0   218.5
  
  vp9_loop_filter_mix2_v_88_16_neon :   302.0   218.2
  
  vp9_loop_filter_v_4_8_neon :           89.0    88.7
  
  vp9_loop_filter_v_8_8_neon :          141.0   137.7
  
  vp9_loop_filter_v_16_8_neon :         295.0   272.7
  
  vp9_loop_filter_v_16_16_neon :        546.0   453.7
  The speedup vs C code in checkasm tests is around 2-7x, which is
  
  pretty much the same as for the 32 bit version. Even if these functions
  
  are faster than their 32 bit equivalent, the C version that we compare
  
  to also became around 1.3-1.7x faster than the C version in 32 bit.
  Based on START_TIMER/STOP_TIMER wrapping around a few individual
  
  functions, the speedup vs C code is around 4-5x.
  Examples of runtimes vs C on a Cortex A57 (for a slightly older version
  
  of the patch) :
  
                           A57 gcc-5.3  neon
  
  loop_filter_h_4_8_neon :        256.6  93.4
  
  loop_filter_h_8_8_neon :        307.3 139.1
  
  loop_filter_h_16_8_neon :       340.1 254.1
  
  loop_filter_h_16_16_neon :      827.0 407.9
  
  loop_filter_mix2_h_44_16_neon : 524.5 155.4
  
  loop_filter_mix2_h_48_16_neon : 644.5 173.3
  
  loop_filter_mix2_h_84_16_neon : 630.5 222.0
  
  loop_filter_mix2_h_88_16_neon : 697.3 222.0
  
  loop_filter_mix2_v_44_16_neon : 598.5 100.6
  
  loop_filter_mix2_v_48_16_neon : 651.5 127.0
  
  loop_filter_mix2_v_84_16_neon : 591.5 167.1
  
  loop_filter_mix2_v_88_16_neon : 855.1 166.7
  
  loop_filter_v_4_8_neon :        271.7  65.3
  
  loop_filter_v_8_8_neon :        312.5 106.9
  
  loop_filter_v_16_8_neon :       473.3 206.5
  
  loop_filter_v_16_16_neon :      976.1 327.8
  The speed-up compared to the C functions is 2.5 to 6 and the cortex-a57
  
  is again 30-50% faster than the cortex-a53.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DBH] libavcodec/aarch64/Makefile
  • [DBH] libavcodec/aarch64/vp9dsp_init_aarch64.c
  • [DBH] libavcodec/aarch64/vp9lpf_neon.S

• FFmpeg remuxing parts of an audio file

  22 décembre 2022, par zorleone

  I'm trying to remux individual tracks from a FLAC file using the FFmpeg libraries.
I get the starting timestamps from a Cue sheet, I seek to the timestamps using avformat_seek_file. However after writing the packets to output files, they only have data from the beginning of the input file.

  


  This is the code snippet which opens the input FLAC and also creates an output AVFormatContext for each track. I'm guessing the issue is avformat_seek_file, it doesn't seem to do anything, since even though I seek to the beginning of a track, the output file contains data from the beginning of the input.

  


      for(int i = 0; i <= sheet.ntracks; i++) {
        sheet.avfmtctx = avformat_alloc_context();
        if(avformat_open_input(&sheet.avfmtctx, sheet.file, NULL, NULL) < 0) {
            fprintf(stderr,
                    "avformat_open_input(): failed to open %s\n",
                    sheet.file);
            return 1;
        }
        int audio_stream_idx = -1;
        for(int i = 0; i < sheet.avfmtctx->nb_streams; i++) {
            if(sheet.avfmtctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
                audio_stream_idx = i;
                break;
            }
        }
        avformat_find_stream_info(sheet.avfmtctx, NULL);
        AVFormatContext *output;
        char *filepath = title_to_filepath(&sheet.tracks[i], sheet.file);
        avformat_alloc_output_context2(&output, NULL, NULL, filepath);
        AVStream *out_audio_stream = avformat_new_stream(output, NULL);
        avcodec_parameters_copy(out_audio_stream->codecpar,
                                sheet.avfmtctx->streams[audio_stream_idx]->codecpar);

        if(avio_open(&output->pb, filepath, AVIO_FLAG_WRITE) < 0) {
            fprintf(stderr, "Failed to open %s for writing\n", filepath);
            return 1;
        }
        if(avformat_write_header(output, NULL) < 0) {
            fprintf(stderr, "avformat_write_header() failed\n");
            return 1;
        }
        int64_t current_frame = sheet.tracks[i].index;
        int64_t next_track_index = (i < sheet.ntracks) ?
                                   sheet.tracks[i + 1].index :
                                   INT64_MAX;
        if(avformat_seek_file(sheet.avfmtctx,
                           -1,
                           INT64_MIN,
                           current_frame,
                           current_frame,
                           0) < 0) {
            fprintf(stderr, "Failed to seek to the index of track %d\n", i);
            avformat_free_context(sheet.avfmtctx);
            sheet.avfmtctx = NULL;
            av_write_trailer(output);
            avio_closep(&output->pb);
            avformat_free_context(output);
            free(filepath);
            continue;
        }
        AVPacket *pkt = av_packet_alloc();
        int64_t pts_diff = AV_NOPTS_VALUE, dts_diff = AV_NOPTS_VALUE;
        while(current_frame < next_track_index && !avio_feof(output->pb)) {
            int ret;
            if((ret = av_read_frame(sheet.avfmtctx, pkt)) < 0) {
                if(ret != AVERROR_EOF)
                    fprintf(stderr, "av_read_frame() failed: %s\n", av_err2str(ret));
                break;
            }
            if(pkt->stream_index != audio_stream_idx)
                continue;
            // runs only once
            if(pts_diff == AV_NOPTS_VALUE && dts_diff == AV_NOPTS_VALUE) {
                pts_diff = pkt->pts;
                dts_diff = pkt->dts;
            }

            pkt->stream_index = 0; // first and only stream
            pkt->pts -= pts_diff;
            pkt->dts -= dts_diff;
            pkt->pos = -1;
            av_interleaved_write_frame(output, pkt);

            current_frame++;
        }

        avformat_free_context(sheet.avfmtctx);
        sheet.avfmtctx = NULL;

        av_write_trailer(output);
        av_packet_free(&pkt);
        avio_closep(&output->pb);
        avformat_free_context(output);

        free(filepath);
    }



  


  current_frame and next_track_index are calculated from the INDEX lines in the Cue sheet : MM * 60 * 75 + SS * 75 + FF.
Can someone tell me what I'm doing wrong, and how to get the data I need from the input ?

  


• I cannot find any way to convert multiple jpg or png to gif in vb.net using ffmpeg

  4 juillet 2017, par Silvia Fonseca

  Is there anyway i can get multiples png or jpg images to gif using ffmpeg in vb.net
  I have start a new application to capture certain frames from a video but now i want to get all the frames extracted in gif image using ffmpeg.
  This is my code so far :
  I have in fact all ready try like this but not succeed
  I have made some changes and i get the gif file but in empty state
  This is my code so far

  Imports System.Diagnostics
  
  Imports System.ComponentModel
  
  Imports System
  
  Imports System.IO
  
  Public Class Form1
  
  Dim video = ""
  
  Dim startInfo As New ProcessStartInfo("ffmpeg.exe")
  
  Dim frame As Long 'individual frames
  
  Dim tempdir As String = "C:\avitogifconverter\" ' images temp directory
  
  Dim DestPath As String = "C:\avitogifconverter\"
  
  Public Declare Auto Function FindWindowNullClassName Lib "user32.dll" Alias "FindWindow" (ByVal lpClassname As Integer, ByVal lpWindownName As String) As Integer
  
  Dim Counter As Integer = 0
  
  
  
  Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
  
      My.Computer.FileSystem.CreateDirectory(tempdir)
  
      TextBox1.Text = "exp:-->video.avi or webm or flv"
  
      TextBox1.Clear()
  
  
  
  
  
  
  
  End Sub
  
  
  
  
  
  Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
  
      Dim p As Process = Process.Start("cmd", "/k ffmpeg.exe -i " + TextBox1.Text + " -filter:v fps=1/15 C:\avitogifconverter\out%02d.jpg")
  
      p.WaitForExit()
  
  
  
      If p.HasExited Then
  
          MsgBox("The Extraction Are Finish...")
  
      End If
  
  
  
  End Sub
  
  
  
  Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
  
  
  
  End Sub
  
  
  
  Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
  
      Label3.Text = "cmd" + "/k ffmpeg.exe -i " + TextBox1.Text + " -filter:v fps=1/15 C:\avi to gif converter\out%02d.jpg"
  
  End Sub
  
  
  
  Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
  
  
  
  
  
      If (OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK) Then
  
          'TextBox1.Text = OpenFileDialog1.FileName
  
          TextBox1.Text = System.IO.Path.GetFileName(OpenFileDialog1.FileName)
  
      End If
  
      If TextBox1.Text = Nothing Then
  
          Return
  
      End If
  
      If TextBox1.Text <> Nothing Then
  
          'My.Computer.FileSystem.CopyFile(TextBox1.Text, DestPath)
  
      End If
  
  
  
  End Sub
  
  
  
  Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
  
      Dim args As String 'declare args
  
      args = " -framerate 1/5 -i C:\avitogifconverter\out%02d.jpg -c:v libx264 -r 30 -pix_fmt yuv420p C:\avitogifconverter\out.gif "
  
      Dim proc As New Process
  
      Dim proci As New ProcessStartInfo
  
      proci.FileName = My.Application.Info.DirectoryPath & "\ffmpeg.exe"
  
      proci.Arguments = args
  
      proci.WindowStyle = ProcessWindowStyle.Hidden
  
      proci.CreateNoWindow = True
  
      proci.UseShellExecute = False
  
      proc.StartInfo = proci
  
      proc.Start()
  
      Do Until proc.HasExited = True
  
          Me.Text = "Saving"
  
      Loop
  
      Me.Text = "your video done"
  
  
  
      MsgBox("Done")
  
  
  
      'IO.Directory.Delete(tempdir, True)
  
  End Sub
  
  End Class