int is_disabled; ///< the enabled state from the last expression evaluation AVBufferRef *hw_device_ctx; int nb_threads; unsigned ready; int extra_hw_frames; }; 滤镜的上下文结构体,存储了AVFilter 的地址,指向了和它相关的AVFilterGraph ,每个AVFilterContext是通过一种链式结构链接,有AVFilterLink输入...
int nb_coded_side_data; AVBufferRef *hw_frames_ctx; int sub_text_format; int trailing_padding; int64_t max_pixels; AVBufferRef *hw_device_ctx; int hwaccel_flags; int apply_cropping; int extra_hw_frames; int discard_damaged_percentage; int64_t max_samples; int export_side_data; int (...
* For filters which will create hardware frames, sets the device the * filter should create them in. All other filters will ignore this field: * in particular, a filter which consumes or processes hardware frames will * instead use the hw_frames_ctx field in AVFilterLink to carry the * h...
-aframes:等价于frames:a,输出选项,用于指定输出的音频帧数目。 -aq:等价于q:a,老版本为qscale:a,用于设定音频质量。 -atag:等价于tag:a,用于设定音频流的标签。 -af:等价于filter:a,用于设定一个声音的后处理过滤链,其参数为一个描述声音后处理链的字符串。 视频选项# -vframes:等价于frames:v,输出选项...
starts. For such * filters, any hardware frame pools used for output must therefore be * of fixed size. The extra framesset here are on top of any number * that the filter needs internally in order to operate normally * * This field must be set before the graph containing this filter...
(淡入视频的前30帧),按顺序声明了3个选项type、start_frame和nb_frames (3.3)上面两个规则混用 (3.4)如果选项的值本身就是一个列表(例如format滤镜有一个像素格式列表选项),则这种列表通常用“|”分隔 举个例子:将输入视频转换为列表中的任何格式 ffmpeg -i good_scale.mp4 -vf “format=pix_fmts=yuv420p|...
* * This field must be set before the graph containing this filter is * configured. */ int extra_hw_frames; ; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. . 20. 21. 22. 23. 24 25 .27. 28 29 ...
alsa是linux下音频驱动框架。 oss是另外一种音频框架。-ar<freq>设置音频采样率,以HZ为单位-ac<channels>设置音频通道数(单声道、双声道)(2)# ffmpeg-f alsa-ac1-ar44100-idefault-t30out.wav参数介绍:-t30表示录制30秒就自动停止(3)# ffmpeg-f alsa-ac1-ar16000-i hw:0-t10out.wav...
/bin/sh../ffmpeg-4.4/configure \--prefix=`pwd`/../ffmpegbuild \--target-os=linux--arch=x86_64--enable-gpl \--enable-version3 \--disable-stripping \--disable-asm \--enable-shared \--enable-libmp3lame \--extra-cflags="-I`pwd`/../lamebuild/include" \--extra-ldflags="-LIBPATH:...
(淡入视频的前30帧),按顺序声明了3个选项type、start_frame和nb_frames (3.3)上面两个规则混用 (3.4)如果选项的值本身就是一个列表(例如format滤镜有一个像素格式列表选项),则这种列表通常用“|”分隔 举个例子:将输入视频转换为列表中的任何格式 ffmpeg -i good_scale.mp4 -vf "format=pix_fmts=yuv420p|...