两次调用ffmpeg.c的main会导致应用崩溃 [英] Calling ffmpeg.c's main twice causes app crash

问题描述

使用FFmpeg 4.0.2并两次调用其ffmpeg.c's main函数会导致Android应用崩溃(使用FFmpeg共享库和JNI)

Using FFmpeg 4.0.2 and call its ffmpeg.c's main function twice causes Android app crash (using FFmpeg shared libs and JNI)

A/libc: Fatal signal 11 (SIGSEGV), code 1, fault addr 0x0 in tid 20153

虽然对于FFmpeg 3.2.5可以正常工作

Though it works ok for FFmpeg 3.2.5

FFmpeg 4.0.2 main

int main(int argc, char **argv) {
    int i, ret;
    int64_t ti;

    init_dynload();

    register_exit(ffmpeg_cleanup);

    setvbuf(stderr,NULL,_IONBF,0); /* win32 runtime needs this */

    av_log_set_flags(AV_LOG_SKIP_REPEATED);
    parse_loglevel(argc, argv, options);

    if(argc>1 && !strcmp(argv[1], "-d")){
        run_as_daemon=1;
        av_log_set_callback(log_callback_null);
        argc--;
        argv++;
    }

#if CONFIG_AVDEVICE
    avdevice_register_all();
#endif
    avformat_network_init();

    show_banner(argc, argv, options);

    /* parse options and open all input/output files */
    ret = ffmpeg_parse_options(argc, argv);
    if (ret < 0)
        exit_program(1);

    if (nb_output_files <= 0 && nb_input_files == 0) {
        show_usage();
        av_log(NULL, AV_LOG_WARNING, "Use -h to get full help or, even better, run 'man %s'\n", program_name);
        exit_program(1);
    }

    /* file converter / grab */
    if (nb_output_files <= 0) {
        av_log(NULL, AV_LOG_FATAL, "At least one output file must be specified\n");
        exit_program(1);
    }

//     if (nb_input_files == 0) {
//         av_log(NULL, AV_LOG_FATAL, "At least one input file must be specified\n");
//         exit_program(1);
//     }

    for (i = 0; i < nb_output_files; i++) {
        if (strcmp(output_files[i]->ctx->oformat->name, "rtp"))
            want_sdp = 0;
    }

    current_time = ti = getutime();
    if (transcode() < 0)
        exit_program(1);
    ti = getutime() - ti;
    if (do_benchmark) {
        av_log(NULL, AV_LOG_INFO, "bench: utime=%0.3fs\n", ti / 1000000.0);
    }
    av_log(NULL, AV_LOG_DEBUG, "%"PRIu64" frames successfully decoded, %"PRIu64" decoding errors\n",
           decode_error_stat[0], decode_error_stat[1]);
    if ((decode_error_stat[0] + decode_error_stat[1]) * max_error_rate < decode_error_stat[1])
        exit_program(69);

    ffmpeg_cleanup(received_nb_signals ? 255 : main_return_code);
    return main_return_code;
}

FFmpeg 3.2.5 main

int main(int argc, char **argv) {
    av_log(NULL, AV_LOG_WARNING, " Command start");

    int i, ret;
    int64_t ti;
    init_dynload();

    register_exit(ffmpeg_cleanup);

    setvbuf(stderr, NULL, _IONBF, 0); /* win32 runtime needs this */

    av_log_set_flags(AV_LOG_SKIP_REPEATED);
    parse_loglevel(argc, argv, options);

    if (argc > 1 && !strcmp(argv[1], "-d")) {
        run_as_daemon = 1;
        av_log_set_callback(log_callback_null);
        argc--;
        argv++;
    }

    avcodec_register_all();
#if CONFIG_AVDEVICE
    avdevice_register_all();
#endif
    avfilter_register_all();
    av_register_all();
    avformat_network_init();

    av_log(NULL, AV_LOG_WARNING, " Register to complete the codec");

    show_banner(argc, argv, options);

    /* parse options and open all input/output files */
    ret = ffmpeg_parse_options(argc, argv);
    if (ret < 0)
        exit_program(1);

    if (nb_output_files <= 0 && nb_input_files == 0) {
        show_usage();
        av_log(NULL, AV_LOG_WARNING, "Use -h to get full help or, even better, run 'man %s'\n",
               program_name);
        exit_program(1);
    }

    /* file converter / grab */
    if (nb_output_files <= 0) {
        av_log(NULL, AV_LOG_FATAL, "At least one output file must be specified\n");
        exit_program(1);
    }

//     if (nb_input_files == 0) {
//         av_log(NULL, AV_LOG_FATAL, "At least one input file must be specified\n");
//         exit_program(1);
//     }

    for (i = 0; i < nb_output_files; i++) {
        if (strcmp(output_files[i]->ctx->oformat->name, "rtp"))
            want_sdp = 0;
    }

    current_time = ti = getutime();
    if (transcode() < 0)
        exit_program(1);
    ti = getutime() - ti;
    if (do_benchmark) {
        av_log(NULL, AV_LOG_INFO, "bench: utime=%0.3fs\n", ti / 1000000.0);
    }
    av_log(NULL, AV_LOG_DEBUG, "%"PRIu64" frames successfully decoded, %"PRIu64" decoding errors\n",
           decode_error_stat[0], decode_error_stat[1]);
    if ((decode_error_stat[0] + decode_error_stat[1]) * max_error_rate < decode_error_stat[1])
        exit_program(69);

    exit_program(received_nb_signals ? 255 : main_return_code);

    nb_filtergraphs = 0;
    nb_input_streams = 0;
    nb_input_files = 0;
    progress_avio = NULL;


    input_streams = NULL;
    nb_input_streams = 0;
    input_files = NULL;
    nb_input_files = 0;

    output_streams = NULL;
    nb_output_streams = 0;
    output_files = NULL;
    nb_output_files = 0;

    return main_return_code;
}

那么可能是什么问题? FFmpeg 4.0.2似乎没有释放任何内容(在第一个命令后，资源或其静态变量为初始值)

So what could be issue? It seems FFmpeg 4.0.2 doesn't release something (resources or its static variables to initial values after the first command)

推荐答案

从FFmpeg 3.2.5到FFmpeg 4.0.2的下一行添加到主要功能的末尾解决了该问题(我将FFmpeg 3.2.5下载为某人的Android项目以便用户添加这些行)

Adding next lines from FFmpeg 3.2.5 to FFmpeg 4.0.2 to the end of main function solved the problem (I downloaded FFmpeg 3.2.5 as someone's Android project so that user added those lines)

nb_filtergraphs = 0;
nb_input_streams = 0;
nb_input_files = 0;
progress_avio = NULL;

input_streams = NULL;
nb_input_streams = 0;
input_files = NULL;
nb_input_files = 0;

output_streams = NULL;
nb_output_streams = 0;
output_files = NULL;
nb_output_files = 0;

这篇关于两次调用ffmpeg.c的main会导致应用崩溃的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！