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>

1 files changed, 30 insertions, 1 deletions

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;