[FFmpeg-devel] [Internet][PATCH 00/12] Add MediaCodec encoder and NDK MediaCodec support

"zhilizhao(赵志立)" quinkblack at foxmail.com
Fri Nov 11 05:36:37 EET 2022


Ping for review.

> On Oct 24, 2022, at 11:16, Zhao Zhili <quinkblack at foxmail.com> wrote:
> 
> From: Zhao Zhili <zhilizhao at tencent.com>
> 
> Firstly, some bugs were fixed (patch 1-4).
> 
> Patch 5 and 6 make mediacodec_wrapper support Java MediaCodec and NDK
> MediaCodec. The use case I'm considering is run FFmpeg on cmdline without JVM,
> for example, run FFmpeg inside of termux (an Android terminal emulator). It's
> well known that NDK MediaCodec missing some important functions, like get the
> list of codecs, but still useable.
> 
> Patch 7 add NDK MediaCodec decoder support. It can be enabled via options,
> and enabled automatically if no JVM is available.
> 
> Patch 8 add ANativeWindow support to hwcontext_mediacodec. It can be set by
> user, and can be created via AMediaCodec_createPersistentInputSurface
> automatically. This is a preparation for encoder.
> 
> Patch 9 makes MediaCodec decoder to support ANativeWindow directly. It worth
> to note that AVMediaCodecContext has only surface. Although we provided
> av_mediacodec_alloc_context(), we didn't strictly prevent users to allocate
> AVMediaCodecContext on stack. I'm not sure if it's OK to add new field to
> AVMediaCodecContext.
> 
> Patch 10 add MediaCodec encoder support. Frame can be feed to encoder via
> buffer, or via Surface/ANativeWindow. If Surface/ANativeWindow is used, and
> the frames come from our MediaCodec decoder wrapper, we can control it's
> 'render' (send to encoder's surface) via av_mediacodec_release_buffer(). A DTS
> generation strategy works in this case. However, if frames comes from other
> sources, like a camera, there is no way to control the 'render' yet, so DTS is
> missing in this case.
> 
> Finally, we can do mediacodec transcoding with FFmpeg cmdline on Android.
> More importantly, we can do MediaCodec decoder to encoder without copy frames,
> although it's very limited since most of avfilters doesn't work. For example:
> 
> ./ffmpeg -hwaccel mediacodec -hwaccel_output_format mediacodec -i /sdcard/test.mp4 -an -c:v h264_mediacodec -y /sdcard/out.mp4
> 
> Since there is no real AVHWFrameContext implementation in hwcontext_mediacodec.
> there is no hwframe_ctx for mediacodec and av_hwframe_transfer_data() doesn't
> work. So if -hwaccel_output_format isn't being specified like:
> 
> ./ffmpeg -hwaccel mediacodec -i /sdcard/test.mp4 -an -c:v h264_mediacodec -y /sdcard/out.mp4
> 
> It will trigger a crash in av_hwframe_transfer_data. Patch 11 add a check on
> hwframe_ctx. Patch 12 set hwaccel_output_format automatically to avoid such
> case.
> 
> 
> Zhao Zhili (12):
>  avcodec/mediacodec: fix incorrect crop info
>  avcodec/mediacodecdec: don't break out if both input and output port
>    return try again
>  avcodec/mediacodecdec_common: fix misuse av_free/av_freep
>  avcodec/mediacodecdec_common: fix useless av_buffer_unref
>  avcodec/mediacodec_wrapper: separate implementation from interface
>  avcodec/mediacodec: add NDK media codec wrapper
>  avcodec/mediacodecdec: enable NDK mediacodec
>  avutil/hwcontext_mediacodec: add ANativeWindow support
>  avcodec/mediacodec: add ANativeWindow support
>  avcodec: add MediaCodec encoder
>  avutil/hwcontext: verify hw_frames_ctx in transfer_data_alloc
>  fftools/ffmpeg_opt: set default hwaccel_output_format for mediacodec
> 
> Changelog                         |   2 +
> configure                         |   6 +
> fftools/ffmpeg_opt.c              |   4 +
> libavcodec/Makefile               |   2 +
> libavcodec/allcodecs.c            |   2 +
> libavcodec/mediacodec_surface.c   |  46 +-
> libavcodec/mediacodec_surface.h   |   8 +-
> libavcodec/mediacodec_wrapper.c   | 942 +++++++++++++++++++++++++++---
> libavcodec/mediacodec_wrapper.h   | 275 +++++++--
> libavcodec/mediacodecdec.c        |  21 +-
> libavcodec/mediacodecdec_common.c |  35 +-
> libavcodec/mediacodecdec_common.h |   1 +
> libavcodec/mediacodecenc.c        | 495 ++++++++++++++++
> libavcodec/version.h              |   2 +-
> libavutil/hwcontext.c             |   6 +-
> libavutil/hwcontext_mediacodec.c  |  56 +-
> libavutil/hwcontext_mediacodec.h  |  11 +
> libavutil/version.h               |   4 +-
> 18 files changed, 1780 insertions(+), 138 deletions(-)
> create mode 100644 libavcodec/mediacodecenc.c
> 
> -- 
> 2.25.1
> 
> 



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