dnxhddec: implement slice multithreading

Around 3x speedup with 4 threads. Maybe more mb lines should be
batched per thread, but that's good enough for a first try.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

1 files changed, 131 insertions, 88 deletions

diff --git a/libavcodec/dnxhddec.c b/libavcodec/dnxhddec.c
index 22d8c0b785..fa9340721c 100644
--- a/libavcodec/dnxhddec.c
+++ b/libavcodec/dnxhddec.c
@@ -32,10 +32,21 @@
 #include "internal.h"
 #include "thread.h"
 
+typedef struct RowContext {
+    DECLARE_ALIGNED(16, int16_t, blocks)[12][64];
+    int luma_scale[64];
+    int chroma_scale[64];
+    GetBitContext gb;
+    int last_dc[3];
+    int last_qscale;
+} RowContext;
+
 typedef struct DNXHDContext {
     AVCodecContext *avctx;
-    GetBitContext gb;
+    RowContext *rows;
     BlockDSPContext bdsp;
+    const uint8_t* buf;
+    int buf_size;
     int64_t cid;                        ///< compression id
     unsigned int width, height;
     enum AVPixelFormat pix_fmt;
@@ -43,30 +54,29 @@ typedef struct DNXHDContext {
     uint32_t mb_scan_index[68];         /* max for 1080p */
     int cur_field;                      ///< current interlaced field
     VLC ac_vlc, dc_vlc, run_vlc;
-    int last_dc[3];
     IDCTDSPContext idsp;
-    DECLARE_ALIGNED(16, int16_t, blocks)[12][64];
     ScanTable scantable;
     const CIDEntry *cid_table;
     int bit_depth; // 8, 10 or 0 if not initialized at all.
     int is_444;
     int mbaff;
     int act;
-    void (*decode_dct_block)(struct DNXHDContext *ctx, int16_t *block,
+    void (*decode_dct_block)(const struct DNXHDContext *ctx,
+                             RowContext *row, int16_t *block,
                              int n, int qscale);
-    int last_qscale;
-    int luma_scale[64];
-    int chroma_scale[64];
 } DNXHDContext;
 
 #define DNXHD_VLC_BITS 9
 #define DNXHD_DC_VLC_BITS 7
 
-static void dnxhd_decode_dct_block_8(DNXHDContext *ctx, int16_t *block,
+static void dnxhd_decode_dct_block_8(const DNXHDContext *ctx,
+                                     RowContext *row, int16_t *block,
                                      int n, int qscale);
-static void dnxhd_decode_dct_block_10(DNXHDContext *ctx, int16_t *block,
+static void dnxhd_decode_dct_block_10(const DNXHDContext *ctx,
+                                      RowContext *row, int16_t *block,
                                       int n, int qscale);
-static void dnxhd_decode_dct_block_10_444(DNXHDContext *ctx, int16_t *block,
+static void dnxhd_decode_dct_block_10_444(const DNXHDContext *ctx,
+                                          RowContext *row, int16_t *block,
                                           int n, int qscale);
 
 static av_cold int dnxhd_decode_init(AVCodecContext *avctx)
@@ -76,6 +86,11 @@ static av_cold int dnxhd_decode_init(AVCodecContext *avctx)
     ctx->avctx = avctx;
     ctx->cid = -1;
     avctx->colorspace = AVCOL_SPC_BT709;
+
+    ctx->rows = av_mallocz_array(avctx->thread_count, sizeof(RowContext));
+    if (!ctx->rows)
+        return AVERROR(ENOMEM);
+
     return 0;
 }
 
@@ -116,6 +131,20 @@ static int dnxhd_init_vlc(DNXHDContext *ctx, uint32_t cid)
     return 0;
 }
 
+static av_cold int dnxhd_decode_init_thread_copy(AVCodecContext *avctx)
+{
+    DNXHDContext *ctx = avctx->priv_data;
+
+    // make sure VLC tables will be loaded when cid is parsed
+    ctx->cid = -1;
+
+    ctx->rows = av_mallocz_array(avctx->thread_count, sizeof(RowContext));
+    if (!ctx->rows)
+        return AVERROR(ENOMEM);
+
+    return 0;
+}
+
 static int dnxhd_decode_header(DNXHDContext *ctx, AVFrame *frame,
                                const uint8_t *buf, int buf_size,
                                int first_field)
@@ -240,7 +269,8 @@ static int dnxhd_decode_header(DNXHDContext *ctx, AVFrame *frame,
     return 0;
 }
 
-static av_always_inline void dnxhd_decode_dct_block(DNXHDContext *ctx,
+static av_always_inline void dnxhd_decode_dct_block(const DNXHDContext *ctx,
+                                                    RowContext *row,
                                                     int16_t *block, int n,
                                                     int qscale,
                                                     int index_bits,
@@ -254,61 +284,61 @@ static av_always_inline void dnxhd_decode_dct_block(DNXHDContext *ctx,
     const uint8_t *ac_level = ctx->cid_table->ac_level;
     const uint8_t *ac_flags = ctx->cid_table->ac_flags;
     const int eob_index     = ctx->cid_table->eob_index;
-    OPEN_READER(bs, &ctx->gb);
+    OPEN_READER(bs, &row->gb);
 
     if (!ctx->is_444) {
         if (n & 2) {
             component     = 1 + (n & 1);
-            scale = ctx->chroma_scale;
+            scale = row->chroma_scale;
             weight_matrix = ctx->cid_table->chroma_weight;
         } else {
             component     = 0;
-            scale = ctx->luma_scale;
+            scale = row->luma_scale;
             weight_matrix = ctx->cid_table->luma_weight;
         }
     } else {
         component = (n >> 1) % 3;
         if (component) {
-            scale = ctx->chroma_scale;
+            scale = row->chroma_scale;
             weight_matrix = ctx->cid_table->chroma_weight;
         } else {
-            scale = ctx->luma_scale;
+            scale = row->luma_scale;
             weight_matrix = ctx->cid_table->luma_weight;
         }
     }
 
-    UPDATE_CACHE(bs, &ctx->gb);
-    GET_VLC(len, bs, &ctx->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);
+    UPDATE_CACHE(bs, &row->gb);
+    GET_VLC(len, bs, &row->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);
     if (len) {
-        level = GET_CACHE(bs, &ctx->gb);
-        LAST_SKIP_BITS(bs, &ctx->gb, len);
+        level = GET_CACHE(bs, &row->gb);
+        LAST_SKIP_BITS(bs, &row->gb, len);
         sign  = ~level >> 31;
         level = (NEG_USR32(sign ^ level, len) ^ sign) - sign;
-        ctx->last_dc[component] += level;
+        row->last_dc[component] += level;
     }
-    block[0] = ctx->last_dc[component];
+    block[0] = row->last_dc[component];
 
     i = 0;
 
-    UPDATE_CACHE(bs, &ctx->gb);
-    GET_VLC(index1, bs, &ctx->gb, ctx->ac_vlc.table,
+    UPDATE_CACHE(bs, &row->gb);
+    GET_VLC(index1, bs, &row->gb, ctx->ac_vlc.table,
             DNXHD_VLC_BITS, 2);
 
     while (index1 != eob_index) {
         level = ac_level[index1];
         flags = ac_flags[index1];
 
-        sign = SHOW_SBITS(bs, &ctx->gb, 1);
-        SKIP_BITS(bs, &ctx->gb, 1);
+        sign = SHOW_SBITS(bs, &row->gb, 1);
+        SKIP_BITS(bs, &row->gb, 1);
 
         if (flags & 1) {
-            level += SHOW_UBITS(bs, &ctx->gb, index_bits) << 7;
-            SKIP_BITS(bs, &ctx->gb, index_bits);
+            level += SHOW_UBITS(bs, &row->gb, index_bits) << 7;
+            SKIP_BITS(bs, &row->gb, index_bits);
         }
 
         if (flags & 2) {
-            UPDATE_CACHE(bs, &ctx->gb);
-            GET_VLC(index2, bs, &ctx->gb, ctx->run_vlc.table,
+            UPDATE_CACHE(bs, &row->gb);
+            GET_VLC(index2, bs, &row->gb, ctx->run_vlc.table,
                     DNXHD_VLC_BITS, 2);
             i += ctx->cid_table->run[index2];
         }
@@ -326,34 +356,37 @@ static av_always_inline void dnxhd_decode_dct_block(DNXHDContext *ctx,
 
         block[j] = (level ^ sign) - sign;
 
-        UPDATE_CACHE(bs, &ctx->gb);
-        GET_VLC(index1, bs, &ctx->gb, ctx->ac_vlc.table,
+        UPDATE_CACHE(bs, &row->gb);
+        GET_VLC(index1, bs, &row->gb, ctx->ac_vlc.table,
                 DNXHD_VLC_BITS, 2);
     }
 
-    CLOSE_READER(bs, &ctx->gb);
+    CLOSE_READER(bs, &row->gb);
 }
 
-static void dnxhd_decode_dct_block_8(DNXHDContext *ctx, int16_t *block,
+static void dnxhd_decode_dct_block_8(const DNXHDContext *ctx,
+                                     RowContext *row, int16_t *block,
                                      int n, int qscale)
 {
-    dnxhd_decode_dct_block(ctx, block, n, qscale, 4, 32, 6);
+    dnxhd_decode_dct_block(ctx, row, block, n, qscale, 4, 32, 6);
 }
 
-static void dnxhd_decode_dct_block_10(DNXHDContext *ctx, int16_t *block,
+static void dnxhd_decode_dct_block_10(const DNXHDContext *ctx,
+                                      RowContext *row, int16_t *block,
                                       int n, int qscale)
 {
-    dnxhd_decode_dct_block(ctx, block, n, qscale, 6, 8, 4);
+    dnxhd_decode_dct_block(ctx, row, block, n, qscale, 6, 8, 4);
 }
 
-static void dnxhd_decode_dct_block_10_444(DNXHDContext *ctx, int16_t *block,
+static void dnxhd_decode_dct_block_10_444(const DNXHDContext *ctx,
+                                          RowContext *row, int16_t *block,
                                           int n, int qscale)
 {
-    dnxhd_decode_dct_block(ctx, block, n, qscale, 6, 32, 6);
+    dnxhd_decode_dct_block(ctx, row, block, n, qscale, 6, 32, 6);
 }
 
-static int dnxhd_decode_macroblock(DNXHDContext *ctx, AVFrame *frame,
-                                   int x, int y)
+static int dnxhd_decode_macroblock(const DNXHDContext *ctx, RowContext *row,
+                                   AVFrame *frame, int x, int y)
 {
     int shift1 = ctx->bit_depth == 10;
     int dct_linesize_luma   = frame->linesize[0];
@@ -364,11 +397,11 @@ static int dnxhd_decode_macroblock(DNXHDContext *ctx, AVFrame *frame,
     int interlaced_mb = 0;
 
     if (ctx->mbaff) {
-        interlaced_mb = get_bits1(&ctx->gb);
-        qscale = get_bits(&ctx->gb, 10);
+        interlaced_mb = get_bits1(&row->gb);
+        qscale = get_bits(&row->gb, 10);
     } else
-    qscale = get_bits(&ctx->gb, 11);
-    act = get_bits1(&ctx->gb);
+        qscale = get_bits(&row->gb, 11);
+    act = get_bits1(&row->gb);
     if (act) {
         static int warned = 0;
         if (!warned) {
@@ -378,22 +411,22 @@ static int dnxhd_decode_macroblock(DNXHDContext *ctx, AVFrame *frame,
         }
     }
 
-    if (qscale != ctx->last_qscale) {
+    if (qscale != row->last_qscale) {
         for (i = 0; i < 64; i++) {
-            ctx->luma_scale[i]   = qscale * ctx->cid_table->luma_weight[i];
-            ctx->chroma_scale[i] = qscale * ctx->cid_table->chroma_weight[i];
+            row->luma_scale[i]   = qscale * ctx->cid_table->luma_weight[i];
+            row->chroma_scale[i] = qscale * ctx->cid_table->chroma_weight[i];
         }
-        ctx->last_qscale = qscale;
+        row->last_qscale = qscale;
     }
 
     for (i = 0; i < 8; i++) {
-        ctx->bdsp.clear_block(ctx->blocks[i]);
-        ctx->decode_dct_block(ctx, ctx->blocks[i], i, qscale);
+        ctx->bdsp.clear_block(row->blocks[i]);
+        ctx->decode_dct_block(ctx, row, row->blocks[i], i, qscale);
     }
     if (ctx->is_444) {
         for (; i < 12; i++) {
-            ctx->bdsp.clear_block(ctx->blocks[i]);
-            ctx->decode_dct_block(ctx, ctx->blocks[i], i, qscale);
+            ctx->bdsp.clear_block(row->blocks[i]);
+            ctx->decode_dct_block(ctx, row, row->blocks[i], i, qscale);
         }
     }
 
@@ -419,55 +452,58 @@ static int dnxhd_decode_macroblock(DNXHDContext *ctx, AVFrame *frame,
     dct_y_offset = interlaced_mb ? frame->linesize[0] : (dct_linesize_luma << 3);
     dct_x_offset = 8 << shift1;
     if (!ctx->is_444) {
-        ctx->idsp.idct_put(dest_y,                               dct_linesize_luma, ctx->blocks[0]);
-        ctx->idsp.idct_put(dest_y + dct_x_offset,                dct_linesize_luma, ctx->blocks[1]);
-        ctx->idsp.idct_put(dest_y + dct_y_offset,                dct_linesize_luma, ctx->blocks[4]);
-        ctx->idsp.idct_put(dest_y + dct_y_offset + dct_x_offset, dct_linesize_luma, ctx->blocks[5]);
+        ctx->idsp.idct_put(dest_y,                               dct_linesize_luma, row->blocks[0]);
+        ctx->idsp.idct_put(dest_y + dct_x_offset,                dct_linesize_luma, row->blocks[1]);
+        ctx->idsp.idct_put(dest_y + dct_y_offset,                dct_linesize_luma, row->blocks[4]);
+        ctx->idsp.idct_put(dest_y + dct_y_offset + dct_x_offset, dct_linesize_luma, row->blocks[5]);
 
         if (!(ctx->avctx->flags & AV_CODEC_FLAG_GRAY)) {
             dct_y_offset = interlaced_mb ? frame->linesize[1] : (dct_linesize_chroma << 3);
-            ctx->idsp.idct_put(dest_u,                dct_linesize_chroma, ctx->blocks[2]);
-            ctx->idsp.idct_put(dest_v,                dct_linesize_chroma, ctx->blocks[3]);
-            ctx->idsp.idct_put(dest_u + dct_y_offset, dct_linesize_chroma, ctx->blocks[6]);
-            ctx->idsp.idct_put(dest_v + dct_y_offset, dct_linesize_chroma, ctx->blocks[7]);
+            ctx->idsp.idct_put(dest_u,                dct_linesize_chroma, row->blocks[2]);
+            ctx->idsp.idct_put(dest_v,                dct_linesize_chroma, row->blocks[3]);
+            ctx->idsp.idct_put(dest_u + dct_y_offset, dct_linesize_chroma, row->blocks[6]);
+            ctx->idsp.idct_put(dest_v + dct_y_offset, dct_linesize_chroma, row->blocks[7]);
         }
     } else {
-        ctx->idsp.idct_put(dest_y,                               dct_linesize_luma, ctx->blocks[0]);
-        ctx->idsp.idct_put(dest_y + dct_x_offset,                dct_linesize_luma, ctx->blocks[1]);
-        ctx->idsp.idct_put(dest_y + dct_y_offset,                dct_linesize_luma, ctx->blocks[6]);
-        ctx->idsp.idct_put(dest_y + dct_y_offset + dct_x_offset, dct_linesize_luma, ctx->blocks[7]);
+        ctx->idsp.idct_put(dest_y,                               dct_linesize_luma, row->blocks[0]);
+        ctx->idsp.idct_put(dest_y + dct_x_offset,                dct_linesize_luma, row->blocks[1]);
+        ctx->idsp.idct_put(dest_y + dct_y_offset,                dct_linesize_luma, row->blocks[6]);
+        ctx->idsp.idct_put(dest_y + dct_y_offset + dct_x_offset, dct_linesize_luma, row->blocks[7]);
 
         if (!(ctx->avctx->flags & AV_CODEC_FLAG_GRAY)) {
             dct_y_offset = interlaced_mb ? frame->linesize[1] : (dct_linesize_chroma << 3);
-            ctx->idsp.idct_put(dest_u,                               dct_linesize_chroma, ctx->blocks[2]);
-            ctx->idsp.idct_put(dest_u + dct_x_offset,                dct_linesize_chroma, ctx->blocks[3]);
-            ctx->idsp.idct_put(dest_u + dct_y_offset,                dct_linesize_chroma, ctx->blocks[8]);
-            ctx->idsp.idct_put(dest_u + dct_y_offset + dct_x_offset, dct_linesize_chroma, ctx->blocks[9]);
-            ctx->idsp.idct_put(dest_v,                               dct_linesize_chroma, ctx->blocks[4]);
-            ctx->idsp.idct_put(dest_v + dct_x_offset,                dct_linesize_chroma, ctx->blocks[5]);
-            ctx->idsp.idct_put(dest_v + dct_y_offset,                dct_linesize_chroma, ctx->blocks[10]);
-            ctx->idsp.idct_put(dest_v + dct_y_offset + dct_x_offset, dct_linesize_chroma, ctx->blocks[11]);
+            ctx->idsp.idct_put(dest_u,                               dct_linesize_chroma, row->blocks[2]);
+            ctx->idsp.idct_put(dest_u + dct_x_offset,                dct_linesize_chroma, row->blocks[3]);
+            ctx->idsp.idct_put(dest_u + dct_y_offset,                dct_linesize_chroma, row->blocks[8]);
+            ctx->idsp.idct_put(dest_u + dct_y_offset + dct_x_offset, dct_linesize_chroma, row->blocks[9]);
+            ctx->idsp.idct_put(dest_v,                               dct_linesize_chroma, row->blocks[4]);
+            ctx->idsp.idct_put(dest_v + dct_x_offset,                dct_linesize_chroma, row->blocks[5]);
+            ctx->idsp.idct_put(dest_v + dct_y_offset,                dct_linesize_chroma, row->blocks[10]);
+            ctx->idsp.idct_put(dest_v + dct_y_offset + dct_x_offset, dct_linesize_chroma, row->blocks[11]);
         }
     }
 
     return 0;
 }
 
-static int dnxhd_decode_macroblocks(DNXHDContext *ctx, AVFrame *frame,
-                                    const uint8_t *buf, int buf_size)
+static int dnxhd_decode_row(AVCodecContext *avctx, void *data,
+                            int rownb, int threadnb)
 {
-    int x, y;
-    for (y = 0; y < ctx->mb_height; y++) {
-        ctx->last_dc[0] =
-        ctx->last_dc[1] =
-        ctx->last_dc[2] = 1 << (ctx->bit_depth + 2); // for levels +2^(bitdepth-1)
-        init_get_bits(&ctx->gb, buf + ctx->mb_scan_index[y], (buf_size - ctx->mb_scan_index[y]) << 3);
-        for (x = 0; x < ctx->mb_width; x++) {
-            //START_TIMER;
-            dnxhd_decode_macroblock(ctx, frame, x, y);
-            //STOP_TIMER("decode macroblock");
-        }
+    const DNXHDContext *ctx = avctx->priv_data;
+    uint32_t offset = ctx->mb_scan_index[rownb];
+    RowContext *row = ctx->rows + threadnb;
+    int x;
+
+    row->last_dc[0] =
+    row->last_dc[1] =
+    row->last_dc[2] = 1 << (ctx->bit_depth + 2); // for levels +2^(bitdepth-1)
+    init_get_bits(&row->gb, ctx->buf + offset, (ctx->buf_size - offset) << 3);
+    for (x = 0; x < ctx->mb_width; x++) {
+        //START_TIMER;
+        dnxhd_decode_macroblock(ctx, row, data, x, rownb);
+        //STOP_TIMER("decode macroblock");
     }
+
     return 0;
 }
 
@@ -512,7 +548,9 @@ decode_coding_unit:
         picture->key_frame = 1;
     }
 
-    dnxhd_decode_macroblocks(ctx, picture, buf + 0x280, buf_size - 0x280);
+    ctx->buf_size = buf_size - 0x280;
+    ctx->buf = buf + 0x280;
+    avctx->execute2(avctx, dnxhd_decode_row, picture, NULL, ctx->mb_height);
 
     if (first_field && picture->interlaced_frame) {
         buf      += ctx->cid_table->coding_unit_size;
@@ -532,6 +570,9 @@ static av_cold int dnxhd_decode_close(AVCodecContext *avctx)
     ff_free_vlc(&ctx->ac_vlc);
     ff_free_vlc(&ctx->dc_vlc);
     ff_free_vlc(&ctx->run_vlc);
+
+    av_freep(&ctx->rows);
+
     return 0;
 }
 
@@ -544,5 +585,7 @@ AVCodec ff_dnxhd_decoder = {
     .init           = dnxhd_decode_init,
     .close          = dnxhd_decode_close,
     .decode         = dnxhd_decode_frame,
-    .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
+    .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS |
+                      AV_CODEC_CAP_SLICE_THREADS,
+    .init_thread_copy = ONLY_IF_THREADS_ENABLED(dnxhd_decode_init_thread_copy),
 };