Nsryjdtyk

I'm creating a wrapper for ffmpeg, and it has the following methods:

fun executeCommand(args: Array<String>): AppRunner.AppResult {

    return appRunner.run(ffmpegPath, args)

}





class AppRunner {



    fun run(

        app: String,

        args: Array<String>,

        timeoutAmount: Long = 60000,

        timeoutUnit: TimeUnit = TimeUnit.SECONDS

    ): AppResult {

        val command = mutableListOf(app)

        command.addAll(args)



        val processResult = ProcessBuilder(command)

            .redirectOutput(ProcessBuilder.Redirect.PIPE)

            .redirectError(ProcessBuilder.Redirect.PIPE)

            .start()

            .apply {

                waitFor(timeoutAmount, timeoutUnit)

            }



        val exitCode = processResult.exitValue()

        val stdOut = processResult.inputStream.bufferedReader().readText()

        val stdErr = processResult.errorStream.bufferedReader().readText()



        return AppResult(exitCode, stdOut, stdErr)

    }



}

And:

fun concatenateAudioFiles(files: Collection<File>, outFile: File) {

    val args = mutableListOf<String>()



    files.forEach { file ->

        args.add("-i")

        args.add(file.absolutePath)

    }



    // Create filter

    val filterStringBuilder = StringBuilder()

    filterStringBuilder.append("'")

    files.forEachIndexed { index, _ ->

        filterStringBuilder.append("[$index:0]")

    }

    filterStringBuilder.append("concat=n=")

    filterStringBuilder.append(files.size)

    filterStringBuilder.append(":v=0:a=1[out]")

    filterStringBuilder.append("'")



    args.add("-filter_complex")

    args.add(filterStringBuilder.toString())

    args.add("-map")

    args.add("'[out]'")

    args.add(outFile.absolutePath)

    logger.info { "Filter: ${args.joinToString(" ")}" }

    val result = executeCommand(args.toTypedArray())

    if (!result.isSuccessful()) {

        throw FfmpegException(result.toString())

    }

}

Args generated by this method are OK:

-i silence-0.5.mp3 -i vo_1543189276830.mp3 -i silence-0.5.mp3 -filter_complex '[0:0][1:0][2:0]concat=n=3:v=0:a=1[out]' -map '[out]' vo_final_1543189276833.mp3

And if I run ffmpeg with this args from command line it works fine.

But when running within Kotlin app, it gives the following error:

[AVFilterGraph @ 0x7fd134071500] No such filter: '[0:0][1:0][2:0]concat=n=3:v=0:a=1[out]'

Error initializing complex filters.

Invalid argument

I've already tried to:

1. Check similar questions


2. Escape ' with
   


3. Replace ' with "
   

Result is the same.

FFMPEG 4.1, Kotlin 1.3, Java 1.8, macOS 10.13.6

Well, the solution is to remove ' at all:

fun concatenateAudioFiles(files: Collection<File>, outFile: File) {

    val args = mutableListOf<String>()



    files.forEach { file ->

        args.add("-i")

        args.add(file.absolutePath)

    }



    // Create filter

    val filterStringBuilder = StringBuilder()

    files.forEachIndexed { index, _ ->

        filterStringBuilder.append("[$index:0]")

    }

    filterStringBuilder.append("concat=n=")

    filterStringBuilder.append(files.size)

    filterStringBuilder.append(":v=0:a=1[out]")



    args.add("-filter_complex")

    args.add(filterStringBuilder.toString())

    args.add("-map")

    args.add("[out]")

    args.add(outFile.absolutePath)

    logger.info { "Filter: ${args.joinToString(" ")}" }

    val result = executeCommand(args.toTypedArray())

    if (!result.isSuccessful()) {

        throw FfmpegException(result.toString())

    }

}

I'm sure that happens because ProcessBuilder escapes arguments with ", so they looked like "-filter_complex" "'[0:0][1:0][2:0]concat=n=3:v=0:a=1[out]'", and that's wrong.