iOS使用FFmepeg命令行工具源码实现转码功能

# 可改可不改
SCRATCH="scratch-ffmpeg"
# 可改可不改
# must be an absolute path
THIN=`pwd`/"thin-ffmpeg"

# absolute path to x264 library
#X264=`pwd`/fat-x264

#FDK_AAC=`pwd`/../fdk-aac-build-script-for-iOS/fdk-aac-ios

# 修改 CONFIGURE_FLAGS 为如下
CONFIGURE_FLAGS="--enable-cross-compile \
			--disable-debug \
			--disable-programs \
			--disable-ffmpeg \
			--disable-ffplay \
			--disable-ffprobe \
        --disable-doc \
        --enable-pic \
        --disable-sdl2 \
        --enable-videotoolbox \
        --enable-avresample"
                 
# 只编译如下架构
ARCHS="arm64 x86_64"

#if defined(__x86_64__)
#include "x86_64_config.h"
#else
#include "arm64_config.h"
#endif

typedef void(*FFmpegCallBack)(int64_t, int64_t);

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

// 在 static void ffmpeg_cleanup(int ret) 函数末尾 添加以下代码
#warning 置空相关计数器
    nb_filtergraphs = 0;
    nb_output_files = 0;
    nb_output_streams = 0;
    nb_input_files = 0;
    nb_input_streams = 0;

void exit_program(int ret)
{
    if (program_exit)
        program_exit(ret);
#warning 由于iOS应用是单进程,如果使用 exit 退出进程,则应用会被退出,因此改为退出线程
//    exit(ret);
    pthread_exit(NULL);
}

// 修改 ffmpeg.c 
static int transcode(void)
// 修改如下
static int transcode(FFmpegCallBack callback)

// 修改 ffmpeg.c 
static void print_report(int is_last_report, int64_t timer_start, int64_t cur_time)
// 修改如下
static void print_report(int is_last_report, int64_t timer_start, int64_t cur_time, FFmpegCallBack callback)

// 在如下函数 
static void print_report(int is_last_report, int64_t timer_start, int64_t cur_time, FFmpegCallBack callback) 

// 1685 行位置 添加如下代码
int64_t total_frames_number = input_files[0]->ctx->streams[0]->nb_frames;

// 将 1716 ~ 1717 行代码改为如下代码
if (is_last_report) {
    if (callback != NULL) {
        (*callback)(total_frames_number, total_frames_number);
    }
    av_bprintf(&buf, "L");
} else {
    if (callback != NULL) {
        (*callback)((int64_t)frame_number, total_frames_number);
    }
}

libavcodec/mathops.h
libavcodec/arm/mathops.h
libavcodec/x86/mathops.h

libavutil/thread.h
libavutil/libm.h
libavutil/internal.h
libavutil/timer.h
libavutil/aarch64/timer.h
libavutil/arm/timer.h
libavutil/x86/timer.h
libavutil/x86/asm.h
libavutil/x86/emms.h
libavutil/reverse.h

libavformat/network.h
libavformat/os_support.h
libavformat/url.h

compat/va_copy.h

static NSDate *date = nil;
static void __FFmpegCallBack(int64_t current, int64_t total) {
    NSLog(@"转码进度: %lld/%lld", current, total);
    if ((current / total) >= 1) {
        int64_t time = (int64_t)([NSDate date].timeIntervalSince1970 - date.timeIntervalSince1970);
        int64_t hours = time % (24*3600) / 3600;
        int64_t minutes = time % 3600 / 60;
        int64_t second = time % 60;
        NSLog(@"转码完成, 耗时: %02lld:%02lld:%02lld", hours, minutes, second);
    }
}
- (void)startFFmpeg:(NSArray<NSString *> *)commands {
    @autoreleasepool {
        int argc = (int)commands.count + 1;
        char **argv[argc];
        argv[0] = "ffmpeg";
        int idx = 1;
        for (NSString *cmd in commands) {
            argv[idx] = cmd.UTF8String;
            idx++;
        }
        NSString *finalCommand = [NSString stringWithFormat:@"ffmpeg 运行参数: \nffmpeg %@", [commands componentsJoinedByString:@" "]];
        NSLog(@"%@\n%@", finalCommand, [NSThread currentThread].name);
        date = [NSDate date];
        ffmpeg_main(argc, argv, &__FFmpegCallBack);
    }
}

// 使用 NSThread 线程调用
NSString *input_path = @"xxxx"; // 输入视频路径
NSString *ouput_path = @"xxxx"; // 输出视频路径
NSString *video_size = @"1920x1080"; // 输出视频尺寸
NSString *video_bit_rate = @"6000k"; // 输出视频码率
NSString *video_code = @"h264_videotoolbox"; // 视频编码器
NSString *video_frame_rate = @"30"; // 视频帧率

NSString *audio_bit_rate = @"64k"; // 音频码率
NSString *audio_sample_rate = @"44.1k"; // 音频采样率
NSString *audio_channels = @"1"; // 音频声道数
NSString *audio_code = @"aac"; // 音频编码器
NSArray<NSString *> *commands = @[@"-y",
                                  @"-i",
                                  input_path,
                                  @"-s",
                                  video_size,
                                  @"-b:v",
                                  video_bit_rate,
                                  @"-vcodec",
                                  video_code,
                                  @"-r",
                                  video_frame_rate,
                                  @"-b:a",
                                  audio_bit_rate,
                                  @"-ar",
                                  audio_sample_rate,
                                  @"-ac",
                                  audio_channels,
                                  @"-acodec",
                                  audio_code,
                                  ouput_path];
    
NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(startFFmpeg:) object:commands];
thread.name = @"ffmpeg.transcode.thread";
[thread start];