avcodec: Implement mpeg2 nvdec hwaccel

This is mostly straight-forward. The weird part is that it should
just work for mpeg1, but I see corruption in my test cases, so I'm
going to try and fix that separately.

1 files changed, 152 insertions, 0 deletions

diff --git a/libavcodec/nvdec_mpeg12.c b/libavcodec/nvdec_mpeg12.c
new file mode 100644
index 0000000000..127e843d85
--- /dev/null
+++ b/libavcodec/nvdec_mpeg12.c
@@ -0,0 +1,152 @@
+/*
+ * MPEG-2 HW decode acceleration through NVDEC
+ *
+ * Copyright (c) 2017 Philip Langdale
+ *
+ * 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 "avcodec.h"
+#include "mpegvideo.h"
+#include "nvdec.h"
+#include "decode.h"
+
+static int get_ref_idx(AVFrame *frame)
+{
+    FrameDecodeData *fdd;
+    NVDECFrame *cf;
+
+    if (!frame || !frame->private_ref)
+        return -1;
+
+    fdd = (FrameDecodeData*)frame->private_ref->data;
+    cf  = (NVDECFrame*)fdd->hwaccel_priv;
+    if (!cf)
+        return -1;
+
+    return cf->idx;
+}
+
+static int nvdec_mpeg12_start_frame(AVCodecContext *avctx, const uint8_t *buffer, uint32_t size)
+{
+    MpegEncContext *s = avctx->priv_data;
+
+    NVDECContext      *ctx = avctx->internal->hwaccel_priv_data;
+    CUVIDPICPARAMS     *pp = &ctx->pic_params;
+    CUVIDMPEG2PICPARAMS *ppc = &pp->CodecSpecific.mpeg2;
+    FrameDecodeData *fdd;
+    NVDECFrame *cf;
+    AVFrame *cur_frame = s->current_picture.f;
+
+    int ret, i;
+
+    ret = ff_nvdec_start_frame(avctx, cur_frame);
+    if (ret < 0)
+        return ret;
+
+    fdd = (FrameDecodeData*)cur_frame->private_ref->data;
+    cf  = (NVDECFrame*)fdd->hwaccel_priv;
+
+    *pp = (CUVIDPICPARAMS) {
+        .PicWidthInMbs     = (cur_frame->width  + 15) / 16,
+        .FrameHeightInMbs  = (cur_frame->height + 15) / 16,
+        .CurrPicIdx        = cf->idx,
+
+        .intra_pic_flag    = s->pict_type == AV_PICTURE_TYPE_I,
+        .ref_pic_flag      = s->pict_type == AV_PICTURE_TYPE_I ||
+                             s->pict_type == AV_PICTURE_TYPE_P,
+
+        .CodecSpecific.mpeg2 = {
+            .ForwardRefIdx     = get_ref_idx(s->last_picture.f),
+            .BackwardRefIdx    = get_ref_idx(s->next_picture.f),
+
+            .picture_coding_type        = s->pict_type,
+            .full_pel_forward_vector    = s->full_pel[0],
+            .full_pel_backward_vector   = s->full_pel[1],
+            .f_code                     = { { s->mpeg_f_code[0][0],
+                                              s->mpeg_f_code[0][1] },
+                                            { s->mpeg_f_code[1][0],
+                                              s->mpeg_f_code[1][1] } },
+            .intra_dc_precision         = s->intra_dc_precision,
+            .frame_pred_frame_dct       = s->frame_pred_frame_dct,
+            .concealment_motion_vectors = s->concealment_motion_vectors,
+            .q_scale_type               = s->q_scale_type,
+            .intra_vlc_format           = s->intra_vlc_format,
+            .alternate_scan             = s->alternate_scan,
+            .top_field_first            = s->top_field_first,
+        }
+    };
+
+    for (i = 0; i < 64; ++i) {
+        ppc->QuantMatrixIntra[i] = s->intra_matrix[i];
+        ppc->QuantMatrixInter[i] = s->inter_matrix[i];
+    }
+
+    return 0;
+}
+
+static int nvdec_mpeg12_end_frame(AVCodecContext *avctx)
+{
+    NVDECContext *ctx = avctx->internal->hwaccel_priv_data;
+    int ret = ff_nvdec_end_frame(avctx);
+    ctx->bitstream = NULL;
+    return ret;
+}
+
+static int nvdec_mpeg12_decode_slice(AVCodecContext *avctx, const uint8_t *buffer, uint32_t size)
+{
+    NVDECContext *ctx = avctx->internal->hwaccel_priv_data;
+    void *tmp;
+
+    tmp = av_fast_realloc(ctx->slice_offsets, &ctx->slice_offsets_allocated,
+                          (ctx->nb_slices + 1) * sizeof(*ctx->slice_offsets));
+    if (!tmp)
+        return AVERROR(ENOMEM);
+    ctx->slice_offsets = tmp;
+
+    if (!ctx->bitstream)
+        ctx->bitstream = (uint8_t*)buffer;
+
+    ctx->slice_offsets[ctx->nb_slices] = buffer - ctx->bitstream;
+    ctx->bitstream_len += size;
+    ctx->nb_slices++;
+
+    return 0;
+}
+
+static int nvdec_mpeg12_frame_params(AVCodecContext *avctx,
+                                  AVBufferRef *hw_frames_ctx)
+{
+    // Each frame can at most have one P and one B reference
+    return ff_nvdec_frame_params(avctx, hw_frames_ctx, 2);
+}
+
+#if CONFIG_MPEG2_NVDEC_HWACCEL
+AVHWAccel ff_mpeg2_nvdec_hwaccel = {
+    .name                 = "mpeg2_nvdec",
+    .type                 = AVMEDIA_TYPE_VIDEO,
+    .id                   = AV_CODEC_ID_MPEG2VIDEO,
+    .pix_fmt              = AV_PIX_FMT_CUDA,
+    .start_frame          = nvdec_mpeg12_start_frame,
+    .end_frame            = nvdec_mpeg12_end_frame,
+    .decode_slice         = nvdec_mpeg12_decode_slice,
+    .frame_params         = nvdec_mpeg12_frame_params,
+    .init                 = ff_nvdec_decode_init,
+    .uninit               = ff_nvdec_decode_uninit,
+    .priv_data_size       = sizeof(NVDECContext),
+};
+#endif