qsvdec: add support for HW_DEVICE_CTX method

This allows user set hw_device_ctx instead of hw_frames_ctx for QSV
decoders, hence we may remove the ad-hoc libmfx setup code from FFmpeg.

"-hwaccel_output_format format" is applied to QSV decoders after
removing the ad-hoc libmfx code. In order to keep compatibility with old
commandlines, the default format is set to AV_PIX_FMT_QSV, but this
behavior will be removed in the future. Please set "-hwaccel_output_format qsv"
explicitly if AV_PIX_FMT_QSV is expected.

The normal device stuff works for QSV decoders now, user may use
"-init_hw_device args" to initialise device and "-hwaccel_device
devicename" to select a device for QSV decoders.

"-qsv_device device" which was added for workarounding device selection
in the ad-hoc libmfx code still works

For example:

$> ffmpeg -init_hw_device qsv=qsv:hw_any,child_device=/dev/dri/card0
-hwaccel qsv -c:v h264_qsv -i input.h264  -f null -

/dev/dri/renderD128 is actually open for h264_qsv decoder in the above
command without this patch. After applying this patch, /dev/dri/card0
is used.

$> ffmpeg -init_hw_device vaapi=va:/dev/dri/card0 -init_hw_device
qsv=hw@va -hwaccel_device hw -hwaccel qsv -c:v h264_qsv -i input.h264
-f null -

device hw of type qsv is not usable in the above command without this
patch. After applying this patch, this command works as expected.

Reviewed-by: Soft Works <softworkz@hotmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>

6 files changed, 66 insertions, 116 deletions

diff --git a/fftools/Makefile b/fftools/Makefile
index 5affaa3f56..5234932ab0 100644
--- a/fftools/Makefile
+++ b/fftools/Makefile
@@ -10,7 +10,6 @@ ALLAVPROGS   = $(AVBASENAMES:%=%$(PROGSSUF)$(EXESUF))
 ALLAVPROGS_G = $(AVBASENAMES:%=%$(PROGSSUF)_g$(EXESUF))
 
 OBJS-ffmpeg                        += fftools/ffmpeg_opt.o fftools/ffmpeg_filter.o fftools/ffmpeg_hw.o
-OBJS-ffmpeg-$(CONFIG_LIBMFX)       += fftools/ffmpeg_qsv.o
 ifndef CONFIG_VIDEOTOOLBOX
 OBJS-ffmpeg-$(CONFIG_VDA)          += fftools/ffmpeg_videotoolbox.o
 endif
diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
index d9c0628657..d2dd7ca092 100644
--- a/fftools/ffmpeg.h
+++ b/fftools/ffmpeg.h
@@ -61,7 +61,6 @@ enum HWAccelID {
     HWACCEL_AUTO,
     HWACCEL_GENERIC,
     HWACCEL_VIDEOTOOLBOX,
-    HWACCEL_QSV,
 };
 
 typedef struct HWAccel {
diff --git a/fftools/ffmpeg_hw.c b/fftools/ffmpeg_hw.c
index fc4a5d31d6..6923c4c5a1 100644
--- a/fftools/ffmpeg_hw.c
+++ b/fftools/ffmpeg_hw.c
@@ -339,6 +339,18 @@ int hw_device_setup_for_decode(InputStream *ist)
         } else if (ist->hwaccel_id == HWACCEL_GENERIC) {
             type = ist->hwaccel_device_type;
             dev = hw_device_get_by_type(type);
+
+            // When "-qsv_device device" is used, an internal QSV device named
+            // as "__qsv_device" is created. Another QSV device is created too
+            // if "-init_hw_device qsv=name:device" is used. There are 2 QSV devices
+            // if both "-qsv_device device" and "-init_hw_device qsv=name:device"
+            // are used, hw_device_get_by_type(AV_HWDEVICE_TYPE_QSV) returns NULL.
+            // To keep back-compatibility with the removed ad-hoc libmfx setup code,
+            // call hw_device_get_by_name("__qsv_device") to select the internal QSV
+            // device.
+            if (!dev && type == AV_HWDEVICE_TYPE_QSV)
+                dev = hw_device_get_by_name("__qsv_device");
+
             if (!dev)
                 err = hw_device_init_from_type(type, NULL, &dev);
         } else {
diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
index 34cc6c4fd3..428934a3d8 100644
--- a/fftools/ffmpeg_opt.c
+++ b/fftools/ffmpeg_opt.c
@@ -138,9 +138,6 @@ const HWAccel hwaccels[] = {
 #if CONFIG_VIDEOTOOLBOX
     { "videotoolbox", videotoolbox_init, HWACCEL_VIDEOTOOLBOX, AV_PIX_FMT_VIDEOTOOLBOX },
 #endif
-#if CONFIG_LIBMFX
-    { "qsv",   qsv_init,   HWACCEL_QSV,   AV_PIX_FMT_QSV },
-#endif
     { 0 },
 };
 HWDevice *filter_hw_device;
@@ -571,6 +568,23 @@ static int opt_vaapi_device(void *optctx, const char *opt, const char *arg)
 }
 #endif
 
+#if CONFIG_QSV
+static int opt_qsv_device(void *optctx, const char *opt, const char *arg)
+{
+    const char *prefix = "qsv=__qsv_device:hw_any,child_device=";
+    int err;
+    char *tmp = av_asprintf("%s%s", prefix, arg);
+
+    if (!tmp)
+        return AVERROR(ENOMEM);
+
+    err = hw_device_init_from_string(tmp, NULL);
+    av_free(tmp);
+
+    return err;
+}
+#endif
+
 static int opt_init_hw_device(void *optctx, const char *opt, const char *arg)
 {
     if (!strcmp(arg, "list")) {
@@ -898,6 +912,12 @@ static void add_input_streams(OptionsContext *o, AVFormatContext *ic)
                     "with old commandlines. This behaviour is DEPRECATED and will be removed "
                     "in the future. Please explicitly set \"-hwaccel_output_format cuda\".\n");
                 ist->hwaccel_output_format = AV_PIX_FMT_CUDA;
+            } else if (!hwaccel_output_format && hwaccel && !strcmp(hwaccel, "qsv")) {
+                av_log(NULL, AV_LOG_WARNING,
+                    "WARNING: defaulting hwaccel_output_format to qsv for compatibility "
+                    "with old commandlines. This behaviour is DEPRECATED and will be removed "
+                    "in the future. Please explicitly set \"-hwaccel_output_format qsv\".\n");
+                ist->hwaccel_output_format = AV_PIX_FMT_QSV;
             } else if (hwaccel_output_format) {
                 ist->hwaccel_output_format = av_get_pix_fmt(hwaccel_output_format);
                 if (ist->hwaccel_output_format == AV_PIX_FMT_NONE) {
@@ -3848,7 +3868,7 @@ const OptionDef options[] = {
 #endif
 
 #if CONFIG_QSV
-    { "qsv_device", HAS_ARG | OPT_STRING | OPT_EXPERT, { &qsv_device },
+    { "qsv_device", HAS_ARG | OPT_EXPERT, { .func_arg = opt_qsv_device },
         "set QSV hardware device (DirectX adapter index, DRM path or X11 display name)", "device"},
 #endif
 
diff --git a/fftools/ffmpeg_qsv.c b/fftools/ffmpeg_qsv.c
deleted file mode 100644
index 7bd999d310..0000000000
--- a/fftools/ffmpeg_qsv.c
+++ /dev/null
@@ -1,109 +0,0 @@
-/*
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <mfx/mfxvideo.h>
-#include <stdlib.h>
-
-#include "libavutil/dict.h"
-#include "libavutil/hwcontext.h"
-#include "libavutil/hwcontext_qsv.h"
-#include "libavutil/opt.h"
-#include "libavcodec/qsv.h"
-
-#include "ffmpeg.h"
-
-static AVBufferRef *hw_device_ctx;
-char *qsv_device = NULL;
-
-static int qsv_get_buffer(AVCodecContext *s, AVFrame *frame, int flags)
-{
-    InputStream *ist = s->opaque;
-
-    return av_hwframe_get_buffer(ist->hw_frames_ctx, frame, 0);
-}
-
-static void qsv_uninit(AVCodecContext *s)
-{
-    InputStream *ist = s->opaque;
-    av_buffer_unref(&ist->hw_frames_ctx);
-}
-
-static int qsv_device_init(InputStream *ist)
-{
-    int err;
-    AVDictionary *dict = NULL;
-
-    if (qsv_device) {
-        err = av_dict_set(&dict, "child_device", qsv_device, 0);
-        if (err < 0)
-            return err;
-    }
-
-    err = av_hwdevice_ctx_create(&hw_device_ctx, AV_HWDEVICE_TYPE_QSV,
-                                 ist->hwaccel_device, dict, 0);
-    if (err < 0) {
-        av_log(NULL, AV_LOG_ERROR, "Error creating a QSV device\n");
-        goto err_out;
-    }
-
-err_out:
-    if (dict)
-        av_dict_free(&dict);
-
-    return err;
-}
-
-int qsv_init(AVCodecContext *s)
-{
-    InputStream *ist = s->opaque;
-    AVHWFramesContext *frames_ctx;
-    AVQSVFramesContext *frames_hwctx;
-    int ret;
-
-    if (!hw_device_ctx) {
-        ret = qsv_device_init(ist);
-        if (ret < 0)
-            return ret;
-    }
-
-    av_buffer_unref(&ist->hw_frames_ctx);
-    ist->hw_frames_ctx = av_hwframe_ctx_alloc(hw_device_ctx);
-    if (!ist->hw_frames_ctx)
-        return AVERROR(ENOMEM);
-
-    frames_ctx   = (AVHWFramesContext*)ist->hw_frames_ctx->data;
-    frames_hwctx = frames_ctx->hwctx;
-
-    frames_ctx->width             = FFALIGN(s->coded_width,  32);
-    frames_ctx->height            = FFALIGN(s->coded_height, 32);
-    frames_ctx->format            = AV_PIX_FMT_QSV;
-    frames_ctx->sw_format         = s->sw_pix_fmt;
-    frames_ctx->initial_pool_size = 64 + s->extra_hw_frames;
-    frames_hwctx->frame_type      = MFX_MEMTYPE_VIDEO_MEMORY_DECODER_TARGET;
-
-    ret = av_hwframe_ctx_init(ist->hw_frames_ctx);
-    if (ret < 0) {
-        av_log(NULL, AV_LOG_ERROR, "Error initializing a QSV frame pool\n");
-        return ret;
-    }
-
-    ist->hwaccel_get_buffer = qsv_get_buffer;
-    ist->hwaccel_uninit     = qsv_uninit;
-
-    return 0;
-}
diff --git a/libavcodec/qsvdec.c b/libavcodec/qsvdec.c
index 19a6a776db..8bce9f2cf0 100644
--- a/libavcodec/qsvdec.c
+++ b/libavcodec/qsvdec.c
@@ -99,7 +99,7 @@ static const AVCodecHWConfigInternal *const qsv_hw_configs[] = {
         .public = {
             .pix_fmt     = AV_PIX_FMT_QSV,
             .methods     = AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX |
-                           AV_CODEC_HW_CONFIG_METHOD_AD_HOC,
+                           AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX,
             .device_type = AV_HWDEVICE_TYPE_QSV,
         },
         .hwaccel = NULL,
@@ -248,6 +248,35 @@ static int qsv_decode_preinit(AVCodecContext *avctx, QSVContext *q, enum AVPixel
         q->nb_ext_buffers = user_ctx->nb_ext_buffers;
     }
 
+    if (avctx->hw_device_ctx && !avctx->hw_frames_ctx && ret == AV_PIX_FMT_QSV) {
+        AVHWFramesContext *hwframes_ctx;
+        AVQSVFramesContext *frames_hwctx;
+
+        avctx->hw_frames_ctx = av_hwframe_ctx_alloc(avctx->hw_device_ctx);
+
+        if (!avctx->hw_frames_ctx) {
+            av_log(avctx, AV_LOG_ERROR, "av_hwframe_ctx_alloc failed\n");
+            return AVERROR(ENOMEM);
+        }
+
+        hwframes_ctx = (AVHWFramesContext*)avctx->hw_frames_ctx->data;
+        frames_hwctx = hwframes_ctx->hwctx;
+        hwframes_ctx->width             = FFALIGN(avctx->coded_width,  32);
+        hwframes_ctx->height            = FFALIGN(avctx->coded_height, 32);
+        hwframes_ctx->format            = AV_PIX_FMT_QSV;
+        hwframes_ctx->sw_format         = avctx->sw_pix_fmt;
+        hwframes_ctx->initial_pool_size = 64 + avctx->extra_hw_frames;
+        frames_hwctx->frame_type        = MFX_MEMTYPE_VIDEO_MEMORY_DECODER_TARGET;
+
+        ret = av_hwframe_ctx_init(avctx->hw_frames_ctx);
+
+        if (ret < 0) {
+            av_log(NULL, AV_LOG_ERROR, "Error initializing a QSV frame pool\n");
+            av_buffer_unref(&avctx->hw_frames_ctx);
+            return ret;
+        }
+    }
+
     if (avctx->hw_frames_ctx) {
         AVHWFramesContext    *frames_ctx = (AVHWFramesContext*)avctx->hw_frames_ctx->data;
         AVQSVFramesContext *frames_hwctx = frames_ctx->hwctx;