iOS integrated FFmpeg command line

foreword

This article is the second part of compiling FFmpeg for iOS

integrated into engineering

Find the corresponding file

Change the suffix of Appdelegate.m to .mm to enable the hybrid mode. command+B, if no error is reported, the compilation is successful.

found in ffmpegfftools

found in scratchconfig

to the iOS project

Solve integration error (version 4.2.3)

Add library

ffmpeg.h comments

#include "libavutil/thread.h"

ffmpeg_fliter.c comments

#include "libavresample/avresample.h"

cmdutils.c comments

#include "compat/va_copy.h"
#include "libavresample/avresample.h"
#include "libpostproc/postprocess.h"
#include "libavutil/libm.h"
#include "libavformat/network.h"

PRINT_LIB_INFO(avresample, AVRESAMPLE, flags, level);
PRINT_LIB_INFO(postproc,   POSTPROC,   flags, level);

ffmpeg.c comments

include "libavutil/internal.h"
#include "libavutil/libm.h"
#include "libavutil/thread.h"
#include "libavcodec/mathops.h"
#include "libavformat/os_support.h"

nb0_frames = nb_frames = mid_pred(ost->last_nb0_frames[0],
                                          ost->last_nb0_frames[1],
                                          ost->last_nb0_frames[2]);
                                          
ff_dlog(NULL, "force_key_frame: n:%f n_forced:%f prev_forced_n:%f t:%f prev_forced_t:%f -> res:%f\n",
                    ost->forced_keyframes_expr_const_values[FKF_N],
                    ost->forced_keyframes_expr_const_values[FKF_N_FORCED],
                    ost->forced_keyframes_expr_const_values[FKF_PREV_FORCED_N],
                    ost->forced_keyframes_expr_const_values[FKF_T],
                    ost->forced_keyframes_expr_const_values[FKF_PREV_FORCED_T],
                    res);

ffmpeg.c header import

#include "pthread.h"

ffmpeg.h added

int ffmpeg_main(int argc, char **argv);

mainChange ffmpeg.c toffmpeg_main

Optimize the problem after integration

Counter zeroing problem (the code of ffmpeg.c will access empty attributes and cause the program to crash)

The function ffmpeg.cin find is changed to the followingffmpeg_cleanup

nb_filtergraphs=0;
nb_output_files=0;
nb_output_streams=0;
nb_input_files=0;
nb_input_streams=0;

Crash problem at the end of command execution
The first method (recommended)

• FFmpeg will execute exit_programthe method to end the process by default, but under iOS, only one process can be started. If the process is not processed by default, the app will automatically exit after executing a command, so it needs to be processed.
• In ffmpeg.cthe ffmpeg_mainfunction, just change all calling exit_programfunctions to calling ffmpeg_cleanupfunctions. At this point, we can use the commands provided by FFmpeg (〃'▽'〃)

The second method

• This method requires 2 files

The function in cmdutils.cis changed to the followingexit_program

void exit_program(int ret)
{
    if (program_exit)
        program_exit(ret);

    //标记为转换完成
    stopRuning();
//这个是结束进程的方法，让ffmpeg进行完转码以后不至于退出程序
//    exit(ret);
//    所以将退出进程的方法改造为退出线程
    pthread_exit(NULL);
}

run

Write OC calls

#import "FFmpegTools.h"
#import "ffmpeg.h"

@implementation FFmpegTools

///执行ffmpeg指令，" "为分割标记符
+ (void)runCmd:(NSString *)commandStr completionBlock:(void(^)(int result))completionBlock {
    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        // 根据 " " 将指令分割为指令数组
        NSArray *argv_array = [commandStr componentsSeparatedByString:(@" ")];
        // 将OC对象转换为对应的C对象
        int argc = (int)argv_array.count;
        char** argv = (char**)malloc(sizeof(char*)*argc);
        for(int i=0; i < argc; i++) {
            argv[i] = (char*)malloc(sizeof(char)*1024);
            strcpy(argv[i],[[argv_array objectAtIndex:i] UTF8String]);
        }
        
//        ffmpeg_main
        // 传入指令数及指令数组,result==0表示成功
        int result = ffmpeg_main(argc,argv);
        NSLog(@"执行FFmpeg命令：%@，result = %d",commandStr,result);
        dispatch_async(dispatch_get_main_queue(), ^{
            completionBlock(result);
        });
    });
}

@end

run code

 NSString *inputPath = [[NSBundle mainBundle] pathForResource:@"123.ts" ofType:nil];
    NSString *docDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
    NSString *outputPath = [docDir stringByAppendingPathComponent:@"videoConver2.mov"];
    NSString *commandStr = [NSString stringWithFormat:@"ffmpeg -i %@ -b:v 2000K -y %@", inputPath, outputPath];
    NSLog(@"执行1");
    [FFmpegTools runCmd:commandStr completionBlock:^(int result) {
        // 0表示成功
        NSLog(@"结果%d",result);
    }];
    NSLog(@"执行2");

Original  iOS integrated FFmpeg command line - Nuggets

★The business card at the end of the article can receive free audio and video development learning materials, including (FFmpeg, webRTC, rtmp, hls, rtsp, ffplay, srs) and audio and video learning roadmaps, etc.

see below!