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• Determine if FFmpeg ran successfully [duplicate]

  31 janvier 2021, par Spedwards

  I have a script I've been using to transcode videos from h264 to h265 in order to preserve space. A lot of manual effort is required to go through and delete the larger files (not always the h264 version). If I was able to determine whether or not FFmpeg finished successfully, I'd be able to save myself a lot of time.

  


  I'll cut out a lot of stuff that's not relevant to the question but below you'll find my script.

  


  function transcode() {
    output=$(echo "$1" | sed -r 's/^(.+)(\.\w{3})$/\1.h265\2/g');
    ffmpeg # a lot of options (including -hide_banner and -loglevel panic)
    echo "$output";
}

RESET=$(tput sgr0);
YELLOW=$(tput setaf 3);
CYAN=$(tput setaf 6);

for f in *.mp4; do
    original=$(stat -c %s "$f");
    echo "${YELLOW}Transcoding file: ${CYAN}$f${RESET}";
    new_file_name=$(transcode "$f");
    new_file_size=$(stat -c %s "$new_file_name");
    if [[ "$new_file_size" -gt "$original" ]]; then
        rm "$new_file_name";
    fi
    echo "";
done;


  


  Ideally, I'd like to delete the original source file if the transcoded file is smaller and FFmpeg ran successfully. Unfortunately due to various reasons FFmpeg can fail while transcoding.

  


  I have seen a few questions asking similar stuff but implementing it is just going over my head. I can't really be creating text files with the output either (though I guess that can be cleaned up as it goes).

  


  Any help would be greatly appreciated.

  


• How to determine WxH of video using ffprobe java android studio

  15 février 2021, par sara bensarghin

  I'm trying to concatenate two videos on Android. I would like to know how to work with ffprobe to determine WxH of the first video and scaling the second video to the resolution of the first video.

  


          a(new String[]{"-y",
                        "-ss",
                        String.valueOf(this.m),
                        "-t",
                        String.valueOf(this.a),
                        "-i",
                        (String) FileUtils.myUri.get(0),
                        "-ss",
                        String.valueOf(this.n),
                        "-t",
                        String.valueOf(this.b),
                        "-i",
                        (String) FileUtils.myUri.get(1),
                        "-strict",
                        "experimental",
                        "-filter_complex",
                        "[0:v]scale=320x240," +
                                "setsar=1:1[v0];[1:v]scale=320x240,setsar=1:1[v1];[v0][v1] concat=n=2:v=1",
                        "-ab",
                        "48000",
                        "-ac",
                        "2",
                        "-ar",
                        "22050",
                        "-s",
                        "320x240",
                        "-r",
                        "15",
                        "-b",
                        "2097k",
                        "-vcodec",
                        "mpeg4",
                        this.d},
                this.d);
    }



  


• How determine raw AAC frame size without ADTS header in .mp4 ?

  26 août 2022, par isrepeat

  I am trying to restore corrupted video with sound. Video restore good because each video frame consist frist bytes header with size. But in .mp4 AAC saved as raw byte stream without ADTS header.

  


  At first I wanted take all bytes data between 2 video frames and save in as 1 audio frame, but there may be more the one audio frame. Each AAC frame started at 0x21 ... .... So i am tryied split all received data by '0x21' separator, but in not always work because some AAC-samples may consist inside several value = 0x21.

  


  I found out that ffmpeg when read .mp4 format parse moov atom -> ... -> stsz (Sample Size). But if moov atom was lost how I can restore correct AAC sizes for audio frames ?