ffmpeg: Add cuvid hwaccel support

Makefile

@@ -36,6 +36,7 @@ OBJS-ffmpeg-$(CONFIG_VAAPI)   += ffmpeg_vaapi.o
 ifndef CONFIG_VIDEOTOOLBOX
 OBJS-ffmpeg-$(CONFIG_VDA)     += ffmpeg_videotoolbox.o
 endif
+OBJS-ffmpeg-$(CONFIG_CUVID)   += ffmpeg_cuvid.o
 OBJS-ffmpeg-$(HAVE_DXVA2_LIB) += ffmpeg_dxva2.o
 OBJS-ffmpeg-$(HAVE_VDPAU_X11) += ffmpeg_vdpau.o
 OBJS-ffserver                 += ffserver_config.o

ffmpeg.c

@@ -3063,6 +3063,11 @@ static int transcode_init(void)
                 exit_program(1);
 #endif
 
+#if CONFIG_CUVID
+            if (cuvid_transcode_init(ost))
+                exit_program(1);
+#endif
+
             if (!ost->filter &&
                 (enc_ctx->codec_type == AVMEDIA_TYPE_VIDEO ||
                  enc_ctx->codec_type == AVMEDIA_TYPE_AUDIO)) {

ffmpeg.h

@@ -66,6 +66,7 @@ enum HWAccelID {
     HWACCEL_VIDEOTOOLBOX,
     HWACCEL_QSV,
     HWACCEL_VAAPI,
+    HWACCEL_CUVID,
 };
 
 typedef struct HWAccel {
@@ -585,5 +586,7 @@ int qsv_init(AVCodecContext *s);
 int qsv_transcode_init(OutputStream *ost);
 int vaapi_decode_init(AVCodecContext *avctx);
 int vaapi_device_init(const char *device);
+int cuvid_init(AVCodecContext *s);
+int cuvid_transcode_init(OutputStream *ost);
 
 #endif /* FFMPEG_H */

ffmpeg_cuvid.c

@@ -0,0 +1,237 @@
+/*
+ * 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 "libavutil/hwcontext.h"
+#include "libavutil/hwcontext_cuda.h"
+
+#include "ffmpeg.h"
+
+#include <cuda.h>
+#include <nvcuvid.h>
+
+typedef struct CUVIDContext {
+    AVBufferRef *hw_frames_ctx;
+} CUVIDContext;
+
+static void cuvid_uninit(AVCodecContext *avctx)
+{
+    InputStream  *ist = avctx->opaque;
+    CUVIDContext *ctx = ist->hwaccel_ctx;
+
+    if (ctx) {
+        av_buffer_unref(&ctx->hw_frames_ctx);
+        av_freep(&ctx);
+    }
+
+    av_buffer_unref(&ist->hw_frames_ctx);
+
+    ist->hwaccel_ctx = 0;
+    ist->hwaccel_uninit = 0;
+}
+
+int cuvid_init(AVCodecContext *avctx)
+{
+    InputStream  *ist = avctx->opaque;
+    CUVIDContext *ctx = ist->hwaccel_ctx;
+
+    av_log(NULL, AV_LOG_TRACE, "Initializing cuvid hwaccel\n");
+
+    if (!ctx) {
+        av_log(NULL, AV_LOG_ERROR, "CUVID transcoding is not initialized. "
+               "-hwaccel cuvid should only be used for one-to-one CUVID transcoding "
+               "with no (software) filters.\n");
+        return AVERROR(EINVAL);
+    }
+
+    return 0;
+}
+
+static void cuvid_ctx_free(AVHWDeviceContext *ctx)
+{
+    AVCUDADeviceContext *hwctx = ctx->hwctx;
+    cuCtxDestroy(hwctx->cuda_ctx);
+}
+
+int cuvid_transcode_init(OutputStream *ost)
+{
+    InputStream *ist;
+    const enum AVPixelFormat *pix_fmt;
+    AVCUDADeviceContext *device_hwctx;
+    AVHWDeviceContext *device_ctx;
+    AVHWFramesContext *hwframe_ctx;
+    CUVIDContext *ctx = NULL;
+    CUdevice device;
+    CUcontext cuda_ctx = NULL;
+    CUcontext dummy;
+    CUresult err;
+    int ret = 0;
+
+    av_log(NULL, AV_LOG_TRACE, "Initializing cuvid transcoding\n");
+
+    if (ost->source_index < 0)
+        return 0;
+
+    ist = input_streams[ost->source_index];
+
+    /* check if the encoder supports CUVID */
+    if (!ost->enc->pix_fmts)
+        goto cancel;
+    for (pix_fmt = ost->enc->pix_fmts; *pix_fmt != AV_PIX_FMT_NONE; pix_fmt++)
+        if (*pix_fmt == AV_PIX_FMT_CUDA)
+            break;
+    if (*pix_fmt == AV_PIX_FMT_NONE)
+        goto cancel;
+
+    /* check if the decoder supports CUVID */
+    if (ist->hwaccel_id != HWACCEL_CUVID || !ist->dec || !ist->dec->pix_fmts)
+        goto cancel;
+    for (pix_fmt = ist->dec->pix_fmts; *pix_fmt != AV_PIX_FMT_NONE; pix_fmt++)
+        if (*pix_fmt == AV_PIX_FMT_CUDA)
+            break;
+    if (*pix_fmt == AV_PIX_FMT_NONE)
+        goto cancel;
+
+    av_log(NULL, AV_LOG_VERBOSE, "Setting up CUVID transcoding\n");
+
+    if (ist->hwaccel_ctx) {
+        ctx = ist->hwaccel_ctx;
+    } else {
+        ctx = av_mallocz(sizeof(*ctx));
+        if (!ctx) {
+            ret = AVERROR(ENOMEM);
+            goto error;
+        }
+    }
+
+    if (!hw_device_ctx) {
+        hw_device_ctx = av_hwdevice_ctx_alloc(AV_HWDEVICE_TYPE_CUDA);
+        if (!hw_device_ctx) {
+            av_log(NULL, AV_LOG_ERROR, "av_hwdevice_ctx_alloc(AV_HWDEVICE_TYPE_CUDA) failed\n");
+            ret = AVERROR(ENOMEM);
+            goto error;
+        }
+
+        err = cuInit(0);
+        if (err != CUDA_SUCCESS) {
+            av_log(NULL, AV_LOG_ERROR, "Could not initialize the CUDA driver API\n");
+            ret = AVERROR_UNKNOWN;
+            goto error;
+        }
+
+        err = cuDeviceGet(&device, 0); ///TODO: Make device index configurable
+        if (err != CUDA_SUCCESS) {
+            av_log(NULL, AV_LOG_ERROR, "Could not get the device number %d\n", 0);
+            ret = AVERROR_UNKNOWN;
+            goto error;
+        }
+
+        err = cuCtxCreate(&cuda_ctx, CU_CTX_SCHED_BLOCKING_SYNC, device);
+        if (err != CUDA_SUCCESS) {
+            av_log(NULL, AV_LOG_ERROR, "Error creating a CUDA context\n");
+            ret = AVERROR_UNKNOWN;
+            goto error;
+        }
+
+        device_ctx = (AVHWDeviceContext*)hw_device_ctx->data;
+        device_ctx->free = cuvid_ctx_free;
+
+        device_hwctx = device_ctx->hwctx;
+        device_hwctx->cuda_ctx = cuda_ctx;
+
+        err = cuCtxPopCurrent(&dummy);
+        if (err != CUDA_SUCCESS) {
+            av_log(NULL, AV_LOG_ERROR, "cuCtxPopCurrent failed\n");
+            ret = AVERROR_UNKNOWN;
+            goto error;
+        }
+
+        ret = av_hwdevice_ctx_init(hw_device_ctx);
+        if (ret < 0) {
+            av_log(NULL, AV_LOG_ERROR, "av_hwdevice_ctx_init failed\n");
+            goto error;
+        }
+    } else {
+        device_ctx = (AVHWDeviceContext*)hw_device_ctx->data;
+        device_hwctx = device_ctx->hwctx;
+        cuda_ctx = device_hwctx->cuda_ctx;
+    }
+
+    if (device_ctx->type != AV_HWDEVICE_TYPE_CUDA) {
+        av_log(NULL, AV_LOG_ERROR, "Hardware device context is already initialized for a diffrent hwaccel.\n");
+        ret = AVERROR(EINVAL);
+        goto error;
+    }
+
+    if (!ctx->hw_frames_ctx) {
+        ctx->hw_frames_ctx = av_hwframe_ctx_alloc(hw_device_ctx);
+        if (!ctx->hw_frames_ctx) {
+            av_log(NULL, AV_LOG_ERROR, "av_hwframe_ctx_alloc failed\n");
+            ret = AVERROR(ENOMEM);
+            goto error;
+        }
+    }
+
+    /* This is a bit hacky, av_hwframe_ctx_init is called by the cuvid decoder
+     * once it has probed the neccesary format information. But as filters/nvenc
+     * need to know the format/sw_format, set them here so they are happy.
+     * This is fine as long as CUVID doesn't add another supported pix_fmt.
+     */
+    hwframe_ctx = (AVHWFramesContext*)ctx->hw_frames_ctx->data;
+    hwframe_ctx->format = AV_PIX_FMT_CUDA;
+    hwframe_ctx->sw_format = AV_PIX_FMT_NV12;
+
+    ost->hwaccel_ctx = ctx;
+    ost->enc_ctx->hw_frames_ctx = av_buffer_ref(ctx->hw_frames_ctx);
+    ost->enc_ctx->pix_fmt = AV_PIX_FMT_CUDA;
+
+    if (!ost->enc_ctx->hw_frames_ctx) {
+        av_log(NULL, AV_LOG_ERROR, "av_buffer_ref failed\n");
+        ret = AVERROR(ENOMEM);
+        goto error;
+    }
+
+    if (!ist->hwaccel_ctx) {
+        ist->hwaccel_ctx = ctx;
+        ist->hw_frames_ctx = av_buffer_ref(ctx->hw_frames_ctx);
+        ist->dec_ctx->hw_frames_ctx = av_buffer_ref(ctx->hw_frames_ctx);
+        ist->dec_ctx->pix_fmt = AV_PIX_FMT_CUDA;
+        ist->resample_pix_fmt = AV_PIX_FMT_CUDA;
+
+        ist->hwaccel_uninit = cuvid_uninit;
+
+        if (!ist->hw_frames_ctx || !ist->dec_ctx->hw_frames_ctx) {
+            av_log(NULL, AV_LOG_ERROR, "av_buffer_ref failed\n");
+            ret = AVERROR(ENOMEM);
+            goto error;
+        }
+    }
+
+    return 0;
+
+error:
+    av_freep(&ctx);
+    return ret;
+
+cancel:
+    if (ist->hwaccel_id == HWACCEL_CUVID) {
+        av_log(NULL, AV_LOG_ERROR, "CUVID hwaccel requested, but impossible to achive.\n");
+        return AVERROR(EINVAL);
+    }
+
+    return 0;
+}

ffmpeg_opt.c

@@ -83,6 +83,9 @@ const HWAccel hwaccels[] = {
 #endif
 #if CONFIG_VAAPI
     { "vaapi", vaapi_decode_init, HWACCEL_VAAPI, AV_PIX_FMT_VAAPI },
+#endif
+#if CONFIG_CUVID
+    { "cuvid", cuvid_init, HWACCEL_CUVID, AV_PIX_FMT_CUDA },
 #endif
     { 0 },
 };