Add support for V4L2 mem2mem codecs.

Default buffer settings should work with all drivers (mmaped memory from the driver) but would imply useless memcpy()'s if used in the standard way.
libavcodec/v4l2.h is now installed to allow applications to get the proper buffers to avoid these copies.

This has been tested on MFC5, on a Samsung exynos 4412 SOC (odroid u3).

Author: Alexis Ballier <aballier@gentoo.org>

Changelog

@@ -45,7 +45,7 @@ version 2.8.6
 - ffmdec: reset packet_end in case of failure
 - avformat/ipmovie: put video decoding_map_size into packet and use it in decoder
 - avformat/brstm: fix overflow
-
+- V4L2 mem2mem HW accelerated codecs support
 
 version 2.8.5
 - avformat/hls: Even stricter URL checks

configure

@@ -152,6 +152,7 @@ Component options:
 Hardware accelerators:
   --disable-d3d11va        disable D3D11VA code [autodetect]
   --disable-dxva2          disable DXVA2 code [autodetect]
+  --disable-v4l2_m2m       disable V4L2 mem2mem code [autodetect]
   --disable-vaapi          disable VAAPI code [autodetect]
   --disable-vda            disable VDA code [autodetect]
   --disable-vdpau          disable VDPAU code [autodetect]
@@ -1462,6 +1463,7 @@ FEATURE_LIST="
 HWACCEL_LIST="
     d3d11va
     dxva2
+    v4l2_m2m
     vaapi
     vda
     vdpau
@@ -2143,6 +2145,7 @@ mpegvideoenc_select="me_cmp mpegvideo pixblockdsp qpeldsp"
 qsvdec_select="qsv"
 qsvenc_select="qsv"
 v4l2_deps_any="linux_videodev2_h sys_videoio_h"
+v4l2_m2m_select="v4l2"
 
 # decoders / encoders
 aac_decoder_select="imdct15 mdct sinewin"
@@ -2217,11 +2220,15 @@ h261_decoder_select="mpegvideo"
 h261_encoder_select="aandcttables mpegvideoenc"
 h263_decoder_select="h263_parser h263dsp mpegvideo qpeldsp"
 h263_encoder_select="aandcttables h263dsp mpegvideoenc"
+h263_v4l2m2m_decoder_deps="v4l2_m2m"
+h263_v4l2m2m_encoder_deps="v4l2_m2m"
 h263i_decoder_select="h263_decoder"
 h263p_decoder_select="h263_decoder"
 h263p_encoder_select="h263_encoder"
 h264_decoder_select="cabac golomb h264chroma h264dsp h264pred h264qpel startcode videodsp"
 h264_decoder_suggest="error_resilience"
+h264_v4l2m2m_decoder_deps="v4l2_m2m"
+h264_v4l2m2m_encoder_deps="v4l2_m2m"
 h264_qsv_decoder_deps="libmfx"
 h264_qsv_decoder_select="h264_mp4toannexb_bsf h264_parser qsvdec h264_qsv_hwaccel"
 h264_qsv_encoder_deps="libmfx"
@@ -2270,9 +2277,11 @@ mpc7_decoder_select="bswapdsp mpegaudiodsp"
 mpc8_decoder_select="mpegaudiodsp"
 mpeg_xvmc_decoder_deps="X11_extensions_XvMClib_h"
 mpeg_xvmc_decoder_select="mpeg2video_decoder"
+mpeg1_v4l2m2m_decoder_deps="v4l2_m2m"
 mpegvideo_decoder_select="mpegvideo"
 mpeg1video_decoder_select="mpegvideo"
 mpeg1video_encoder_select="aandcttables mpegvideoenc h263dsp"
+mpeg2_v4l2m2m_decoder_deps="v4l2_m2m"
 mpeg2video_decoder_select="mpegvideo"
 mpeg2video_encoder_select="aandcttables mpegvideoenc h263dsp"
 mpeg2_qsv_decoder_deps="libmfx"
@@ -2281,6 +2290,8 @@ mpeg2_qsv_encoder_deps="libmfx"
 mpeg2_qsv_encoder_select="qsvenc"
 mpeg4_decoder_select="h263_decoder mpeg4video_parser"
 mpeg4_encoder_select="h263_encoder"
+mpeg4_v4l2m2m_decoder_deps="v4l2_m2m"
+mpeg4_v4l2m2m_encoder_deps="v4l2_m2m"
 msa1_decoder_select="mss34dsp"
 msmpeg4v1_decoder_select="h263_decoder"
 msmpeg4v2_decoder_select="h263_decoder"
@@ -2341,6 +2352,7 @@ utvideo_decoder_select="bswapdsp"
 utvideo_encoder_select="bswapdsp huffman huffyuvencdsp"
 vble_decoder_select="huffyuvdsp"
 vc1_decoder_select="blockdsp h263_decoder h264qpel intrax8 qpeldsp startcode"
+vc1_v4l2m2m_decoder_deps="v4l2_m2m"
 vc1image_decoder_select="vc1_decoder"
 vc1_qsv_decoder_deps="libmfx"
 vc1_qsv_decoder_select="qsvdec vc1_qsv_hwaccel"
@@ -2353,6 +2365,8 @@ vp6a_decoder_select="vp6_decoder"
 vp6f_decoder_select="vp6_decoder"
 vp7_decoder_select="h264pred videodsp vp8dsp"
 vp8_decoder_select="h264pred videodsp vp8dsp"
+vp8_v4l2m2m_decoder_deps="v4l2_m2m"
+vp8_v4l2m2m_encoder_deps="v4l2_m2m"
 vp9_decoder_select="videodsp vp9_parser"
 webp_decoder_select="vp8_decoder"
 wmalossless_decoder_select="llauddsp"
@@ -2919,7 +2933,7 @@ sws_max_filter_size_default=256
 set_default sws_max_filter_size
 
 # Enable hwaccels by default.
-enable d3d11va dxva2 vaapi vda vdpau videotoolbox xvmc
+enable d3d11va dxva2 v4l2_m2m vaapi vda vdpau videotoolbox xvmc
 enable xlib
 
 # build settings
@@ -5427,6 +5441,7 @@ check_header linux/fb.h
 check_header linux/videodev.h
 check_header linux/videodev2.h
 check_code cc linux/videodev2.h "struct v4l2_frmsizeenum vfse; vfse.discrete.width = 0;" && enable_safe struct_v4l2_frmivalenum_discrete
+check_code cc linux/videodev2.h "int i = V4L2_CAP_VIDEO_M2M_MPLANE | V4L2_CAP_VIDEO_M2M;" || disable v4l2_m2m
 
 check_header sys/videoio.h
 check_code cc sys/videoio.h "struct v4l2_frmsizeenum vfse; vfse.discrete.width = 0;" && enable_safe struct_v4l2_frmivalenum_discrete

libavcodec/Makefile

@@ -8,6 +8,7 @@ HEADERS = avcodec.h                                                     \
           d3d11va.h                                                     \
           dxva2.h                                                       \
           old_codec_ids.h                                               \
+          v4l2.h                                                        \
           qsv.h                                                         \
           vaapi.h                                                       \
           vda.h                                                         \
@@ -113,7 +114,8 @@ OBJS-$(CONFIG_STARTCODE)               += startcode.o
 OBJS-$(CONFIG_TEXTUREDSP)              += texturedsp.o
 OBJS-$(CONFIG_TEXTUREDSPENC)           += texturedspenc.o
 OBJS-$(CONFIG_TPELDSP)                 += tpeldsp.o
-OBJS-$(CONFIG_V4L2)                    += v4l2-common.o
+OBJS-$(CONFIG_V4L2)                    += v4l2-common.o v4l2-buffers.o
+OBJS-$(CONFIG_V4L2_M2M)                += v4l2_m2m.o
 OBJS-$(CONFIG_VIDEODSP)                += videodsp.o
 OBJS-$(CONFIG_VP3DSP)                  += vp3dsp.o
 OBJS-$(CONFIG_VP56DSP)                 += vp56dsp.o
@@ -288,10 +290,14 @@ OBJS-$(CONFIG_H263_DECODER)            += h263dec.o h263.o ituh263dec.o        \
                                           intelh263dec.o h263data.o
 OBJS-$(CONFIG_H263_ENCODER)            += mpeg4videoenc.o mpeg4video.o  \
                                           h263.o h263data.o ituh263enc.o flvenc.o
+OBJS-$(CONFIG_H263_V4L2M2M_DECODER)    += v4l2_m2m_dec.o
+OBJS-$(CONFIG_H263_V4L2M2M_ENCODER)    += v4l2_m2m_enc.o
 OBJS-$(CONFIG_H264_DECODER)            += h264.o h264_cabac.o h264_cavlc.o \
                                           h264_direct.o h264_loopfilter.o  \
                                           h264_mb.o h264_picture.o h264_ps.o \
                                           h264_refs.o h264_sei.o h264_slice.o
+OBJS-$(CONFIG_H264_V4L2M2M_DECODER)    += v4l2_m2m_dec.o
+OBJS-$(CONFIG_H264_V4L2M2M_ENCODER)    += v4l2_m2m_enc.o
 OBJS-$(CONFIG_H264_MMAL_DECODER)       += mmaldec.o
 OBJS-$(CONFIG_H264_VDA_DECODER)        += vda_h264_dec.o
 OBJS-$(CONFIG_H264_QSV_DECODER)        += qsvdec_h2645.o
@@ -365,13 +371,17 @@ OBJS-$(CONFIG_MP3ON4FLOAT_DECODER)     += mpegaudiodec_float.o mpeg4audio.o
 OBJS-$(CONFIG_MPC7_DECODER)            += mpc7.o mpc.o
 OBJS-$(CONFIG_MPC8_DECODER)            += mpc8.o mpc.o
 OBJS-$(CONFIG_MPEGVIDEO_DECODER)       += mpeg12dec.o mpeg12.o mpeg12data.o
+OBJS-$(CONFIG_MPEG1_V4L2M2M_DECODER)   += v4l2_m2m_dec.o
 OBJS-$(CONFIG_MPEG1VIDEO_DECODER)      += mpeg12dec.o mpeg12.o mpeg12data.o
 OBJS-$(CONFIG_MPEG1VIDEO_ENCODER)      += mpeg12enc.o mpeg12.o
+OBJS-$(CONFIG_MPEG2_V4L2M2M_DECODER)   += v4l2_m2m_dec.o
 OBJS-$(CONFIG_MPEG2VIDEO_DECODER)      += mpeg12dec.o mpeg12.o mpeg12data.o
 OBJS-$(CONFIG_MPEG2VIDEO_ENCODER)      += mpeg12enc.o mpeg12.o
 OBJS-$(CONFIG_MPEG2_QSV_DECODER)       += qsvdec_mpeg2.o
 OBJS-$(CONFIG_MPEG2_QSV_ENCODER)       += qsvenc_mpeg2.o
 OBJS-$(CONFIG_MPEG4_DECODER)           += xvididct.o
+OBJS-$(CONFIG_MPEG4_V4L2M2M_DECODER)   += v4l2_m2m_dec.o
+OBJS-$(CONFIG_MPEG4_V4L2M2M_ENCODER)   += v4l2_m2m_enc.o
 OBJS-$(CONFIG_MPL2_DECODER)            += mpl2dec.o ass.o
 OBJS-$(CONFIG_MSMPEG4V1_DECODER)       += msmpeg4dec.o msmpeg4.o msmpeg4data.o
 OBJS-$(CONFIG_MSMPEG4V2_DECODER)       += msmpeg4dec.o msmpeg4.o msmpeg4data.o
@@ -527,6 +537,7 @@ OBJS-$(CONFIG_VC1_DECODER)             += vc1dec.o vc1_block.o vc1_loopfilter.o
                                           vc1dsp.o \
                                           msmpeg4dec.o msmpeg4.o msmpeg4data.o \
                                           wmv2dsp.o
+OBJS-$(CONFIG_VC1_V4L2M2M_DECODER)     += v4l2_m2m_dec.o
 OBJS-$(CONFIG_VC1_QSV_DECODER)         += qsvdec_vc1.o
 OBJS-$(CONFIG_VCR1_DECODER)            += vcr1.o
 OBJS-$(CONFIG_VMDAUDIO_DECODER)        += vmdaudio.o
@@ -544,6 +555,8 @@ OBJS-$(CONFIG_VP7_DECODER)             += vp8.o vp56rac.o
 OBJS-$(CONFIG_VP8_DECODER)             += vp8.o vp56rac.o
 OBJS-$(CONFIG_VP9_DECODER)             += vp9.o vp9dsp.o vp56rac.o vp9dsp_8bpp.o \
                                           vp9dsp_10bpp.o vp9dsp_12bpp.o
+OBJS-$(CONFIG_VP8_V4L2M2M_DECODER)     += v4l2_m2m_dec.o
+OBJS-$(CONFIG_VP8_V4L2M2M_ENCODER)     += v4l2_m2m_enc.o
 OBJS-$(CONFIG_VPLAYER_DECODER)         += textdec.o ass.o
 OBJS-$(CONFIG_VQA_DECODER)             += vqavideo.o
 OBJS-$(CONFIG_WAVPACK_DECODER)         += wavpack.o

libavcodec/allcodecs.c

@@ -184,10 +184,12 @@ void avcodec_register_all(void)
     REGISTER_ENCDEC (GIF,               gif);
     REGISTER_ENCDEC (H261,              h261);
     REGISTER_ENCDEC (H263,              h263);
+    REGISTER_ENCDEC (H263_V4L2M2M,      h263_v4l2m2m);
     REGISTER_DECODER(H263I,             h263i);
     REGISTER_ENCDEC (H263P,             h263p);
     REGISTER_DECODER(H264,              h264);
     REGISTER_DECODER(H264_CRYSTALHD,    h264_crystalhd);
+    REGISTER_ENCDEC (H264_V4L2M2M,      h264_v4l2m2m);
     REGISTER_DECODER(H264_MMAL,         h264_mmal);
     REGISTER_DECODER(H264_QSV,          h264_qsv);
     REGISTER_DECODER(H264_VDA,          h264_vda);
@@ -230,15 +232,18 @@ void avcodec_register_all(void)
     REGISTER_ENCDEC (MPEG2VIDEO,        mpeg2video);
     REGISTER_ENCDEC (MPEG4,             mpeg4);
     REGISTER_DECODER(MPEG4_CRYSTALHD,   mpeg4_crystalhd);
+    REGISTER_ENCDEC (MPEG4_V4L2M2M,     mpeg4_v4l2m2m);
 #if FF_API_VDPAU
     REGISTER_DECODER(MPEG4_VDPAU,       mpeg4_vdpau);
 #endif
     REGISTER_DECODER(MPEGVIDEO,         mpegvideo);
+    REGISTER_DECODER(MPEG1_V4L2M2M,     mpeg1_v4l2m2m);
 #if FF_API_VDPAU
     REGISTER_DECODER(MPEG_VDPAU,        mpeg_vdpau);
     REGISTER_DECODER(MPEG1_VDPAU,       mpeg1_vdpau);
 #endif
     REGISTER_DECODER(MPEG2_CRYSTALHD,   mpeg2_crystalhd);
+    REGISTER_DECODER(MPEG2_V4L2M2M,     mpeg2_v4l2m2m);
     REGISTER_DECODER(MPEG2_QSV,         mpeg2_qsv);
     REGISTER_DECODER(MSA1,              msa1);
     REGISTER_DECODER(MSMPEG4_CRYSTALHD, msmpeg4_crystalhd);
@@ -318,6 +323,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER(VBLE,              vble);
     REGISTER_DECODER(VC1,               vc1);
     REGISTER_DECODER(VC1_CRYSTALHD,     vc1_crystalhd);
+    REGISTER_DECODER(VC1_V4L2M2M,       vc1_v4l2m2m);
 #if FF_API_VDPAU
     REGISTER_DECODER(VC1_VDPAU,         vc1_vdpau);
 #endif
@@ -333,6 +339,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER(VP6F,              vp6f);
     REGISTER_DECODER(VP7,               vp7);
     REGISTER_DECODER(VP8,               vp8);
+    REGISTER_ENCDEC (VP8_V4L2M2M,       vp8_v4l2m2m);
     REGISTER_DECODER(VP9,               vp9);
     REGISTER_DECODER(VQA,               vqa);
     REGISTER_DECODER(WEBP,              webp);