avcodec: Refactor common nvdec hwaccel logic

The 'simple' hwaccels (not h.264 and hevc) all use the same bitstream
management and reference lookup logic so let's refactor all that into
common functions.

I verified that casting a signed int -1 to unsigned char produces 255
according to the C language specification.

libavcodec/nvdec.c

@@ -475,6 +475,36 @@ finish:
     return ret;
 }
 
+int ff_nvdec_simple_end_frame(AVCodecContext *avctx)
+{
+    NVDECContext *ctx = avctx->internal->hwaccel_priv_data;
+    int ret = ff_nvdec_end_frame(avctx);
+    ctx->bitstream = NULL;
+    return ret;
+}
+
+int ff_nvdec_simple_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;
+}
+
 int ff_nvdec_frame_params(AVCodecContext *avctx,
                           AVBufferRef *hw_frames_ctx,
                           int dpb_size)
@@ -520,3 +550,19 @@ int ff_nvdec_frame_params(AVCodecContext *avctx,
 
     return 0;
 }
+
+int ff_nvdec_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;
+}

libavcodec/nvdec.h

@@ -58,8 +58,12 @@ int ff_nvdec_decode_init(AVCodecContext *avctx);
 int ff_nvdec_decode_uninit(AVCodecContext *avctx);
 int ff_nvdec_start_frame(AVCodecContext *avctx, AVFrame *frame);
 int ff_nvdec_end_frame(AVCodecContext *avctx);
+int ff_nvdec_simple_end_frame(AVCodecContext *avctx);
+int ff_nvdec_simple_decode_slice(AVCodecContext *avctx, const uint8_t *buffer,
+                                 uint32_t size);
 int ff_nvdec_frame_params(AVCodecContext *avctx,
                           AVBufferRef *hw_frames_ctx,
                           int dpb_size);
+int ff_nvdec_get_ref_idx(AVFrame *frame);
 
 #endif /* AVCODEC_NVDEC_H */

libavcodec/nvdec_mpeg12.c

@@ -25,22 +25,6 @@
 #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;
@@ -71,8 +55,8 @@ static int nvdec_mpeg12_start_frame(AVCodecContext *avctx, const uint8_t *buffer
                              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),
+            .ForwardRefIdx     = ff_nvdec_get_ref_idx(s->last_picture.f),
+            .BackwardRefIdx    = ff_nvdec_get_ref_idx(s->next_picture.f),
 
             .picture_coding_type        = s->pict_type,
             .full_pel_forward_vector    = s->full_pel[0],
@@ -99,35 +83,6 @@ static int nvdec_mpeg12_start_frame(AVCodecContext *avctx, const uint8_t *buffer
     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)
 {
@@ -142,8 +97,8 @@ AVHWAccel ff_mpeg2_nvdec_hwaccel = {
     .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,
+    .end_frame            = ff_nvdec_simple_end_frame,
+    .decode_slice         = ff_nvdec_simple_decode_slice,
     .frame_params         = nvdec_mpeg12_frame_params,
     .init                 = ff_nvdec_decode_init,
     .uninit               = ff_nvdec_decode_uninit,

libavcodec/nvdec_vc1.c

@@ -25,20 +25,6 @@
 #include "decode.h"
 #include "vc1.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;
-
-    return cf->idx;
-}
-
 static int nvdec_vc1_start_frame(AVCodecContext *avctx, const uint8_t *buffer, uint32_t size)
 {
     VC1Context *v = avctx->priv_data;
@@ -73,8 +59,8 @@ static int nvdec_vc1_start_frame(AVCodecContext *avctx, const uint8_t *buffer, u
                              s->pict_type == AV_PICTURE_TYPE_P,
 
         .CodecSpecific.vc1 = {
-            .ForwardRefIdx     = get_ref_idx(s->last_picture.f),
-            .BackwardRefIdx    = get_ref_idx(s->next_picture.f),
+            .ForwardRefIdx     = ff_nvdec_get_ref_idx(s->last_picture.f),
+            .BackwardRefIdx    = ff_nvdec_get_ref_idx(s->next_picture.f),
             .FrameWidth        = cur_frame->width,
             .FrameHeight       = cur_frame->height,
 
@@ -117,35 +103,6 @@ static int nvdec_vc1_start_frame(AVCodecContext *avctx, const uint8_t *buffer, u
     return 0;
 }
 
-static int nvdec_vc1_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_vc1_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_vc1_frame_params(AVCodecContext *avctx,
                                   AVBufferRef *hw_frames_ctx)
 {
@@ -159,8 +116,8 @@ AVHWAccel ff_vc1_nvdec_hwaccel = {
     .id                   = AV_CODEC_ID_VC1,
     .pix_fmt              = AV_PIX_FMT_CUDA,
     .start_frame          = nvdec_vc1_start_frame,
-    .end_frame            = nvdec_vc1_end_frame,
-    .decode_slice         = nvdec_vc1_decode_slice,
+    .end_frame            = ff_nvdec_simple_end_frame,
+    .decode_slice         = ff_nvdec_simple_decode_slice,
     .frame_params         = nvdec_vc1_frame_params,
     .init                 = ff_nvdec_decode_init,
     .uninit               = ff_nvdec_decode_uninit,
@@ -174,8 +131,8 @@ AVHWAccel ff_wmv3_nvdec_hwaccel = {
     .id                   = AV_CODEC_ID_WMV3,
     .pix_fmt              = AV_PIX_FMT_CUDA,
     .start_frame          = nvdec_vc1_start_frame,
-    .end_frame            = nvdec_vc1_end_frame,
-    .decode_slice         = nvdec_vc1_decode_slice,
+    .end_frame            = ff_nvdec_simple_end_frame,
+    .decode_slice         = ff_nvdec_simple_decode_slice,
     .frame_params         = nvdec_vc1_frame_params,
     .init                 = ff_nvdec_decode_init,
     .uninit               = ff_nvdec_decode_uninit,

libavcodec/nvdec_vp9.c

@@ -28,20 +28,6 @@
 #include "internal.h"
 #include "vp9shared.h"
 
-static unsigned char get_ref_idx(AVFrame *frame)
-{
-    FrameDecodeData *fdd;
-    NVDECFrame *cf;
-
-    if (!frame || !frame->private_ref)
-        return 255;
-
-    fdd = (FrameDecodeData*)frame->private_ref->data;
-    cf  = (NVDECFrame*)fdd->hwaccel_priv;
-
-    return cf->idx;
-}
-
 static int nvdec_vp9_start_frame(AVCodecContext *avctx, const uint8_t *buffer, uint32_t size)
 {
     VP9SharedContext *h = avctx->priv_data;
@@ -72,9 +58,9 @@ static int nvdec_vp9_start_frame(AVCodecContext *avctx, const uint8_t *buffer, u
             .width                    = cur_frame->width,
             .height                   = cur_frame->height,
 
-            .LastRefIdx               = get_ref_idx(h->refs[h->h.refidx[0]].f),
-            .GoldenRefIdx             = get_ref_idx(h->refs[h->h.refidx[1]].f),
-            .AltRefIdx                = get_ref_idx(h->refs[h->h.refidx[2]].f),
+            .LastRefIdx               = ff_nvdec_get_ref_idx(h->refs[h->h.refidx[0]].f),
+            .GoldenRefIdx             = ff_nvdec_get_ref_idx(h->refs[h->h.refidx[1]].f),
+            .AltRefIdx                = ff_nvdec_get_ref_idx(h->refs[h->h.refidx[2]].f),
 
             .profile                  = h->h.profile,
             .frameContextIdx          = h->h.framectxid,
@@ -176,35 +162,6 @@ static int nvdec_vp9_start_frame(AVCodecContext *avctx, const uint8_t *buffer, u
     return 0;
 }
 
-static int nvdec_vp9_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_vp9_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_vp9_frame_params(AVCodecContext *avctx,
                                   AVBufferRef *hw_frames_ctx)
 {
@@ -218,8 +175,8 @@ AVHWAccel ff_vp9_nvdec_hwaccel = {
     .id                   = AV_CODEC_ID_VP9,
     .pix_fmt              = AV_PIX_FMT_CUDA,
     .start_frame          = nvdec_vp9_start_frame,
-    .end_frame            = nvdec_vp9_end_frame,
-    .decode_slice         = nvdec_vp9_decode_slice,
+    .end_frame            = ff_nvdec_simple_end_frame,
+    .decode_slice         = ff_nvdec_simple_decode_slice,
     .frame_params         = nvdec_vp9_frame_params,
     .init                 = ff_nvdec_decode_init,
     .uninit               = ff_nvdec_decode_uninit,