[FFmpeg-devel] [PATCH v1 1/2] avcodec/v410dec: add the slice threading support

[lance.lmwang at gmail.com]

From: Limin Wang <lance.lmwang at gmail.com>

Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
 libavcodec/v410dec.c | 77 ++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 57 insertions(+), 20 deletions(-)

diff --git a/libavcodec/v410dec.c b/libavcodec/v410dec.c
index 48fab68..a9b17a0 100644
--- a/libavcodec/v410dec.c
+++ b/libavcodec/v410dec.c
@@ -24,6 +24,14 @@
 #include "libavutil/intreadwrite.h"
 #include "avcodec.h"
 #include "internal.h"
+#include "thread.h"
+
+#define MAX_SLICES 32
+typedef struct ThreadData {
+    AVFrame *frame;
+    uint8_t *buf;
+    int stride;
+} ThreadData;
 
 static av_cold int v410_decode_init(AVCodecContext *avctx)
 {
@@ -42,31 +50,30 @@ static av_cold int v410_decode_init(AVCodecContext *avctx)
     return 0;
 }
 
-static int v410_decode_frame(AVCodecContext *avctx, void *data,
-                             int *got_frame, AVPacket *avpkt)
+static int v410_decode_slice(AVCodecContext *avctx, void *arg, int jobnr, int nb_jobs)
 {
-    AVFrame *pic = data;
-    uint8_t *src = avpkt->data;
+    ThreadData *td = arg;
+    AVFrame *pic = td->frame;
+    int stride = td->stride;
+    int thread_count = av_clip(avctx->thread_count, 1, MAX_SLICES);
+    int slice_h = avctx->height / thread_count;
+    int slice_m = avctx->height % thread_count;
+    int slice_start = jobnr * slice_h;
+    int slice_end = slice_start + slice_h;
+    const uint8_t *src = td->buf + stride * slice_start;
     uint16_t *y, *u, *v;
     uint32_t val;
-    int i, j, ret;
-
-    if (avpkt->size < 4 * avctx->height * avctx->width) {
-        av_log(avctx, AV_LOG_ERROR, "Insufficient input data.\n");
-        return AVERROR(EINVAL);
-    }
+    int i, j;
 
-    if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
-        return ret;
+     /* add the remaining slice for the last job */
+    if (jobnr == thread_count - 1)
+        slice_end += slice_m;
 
-    pic->key_frame = 1;
-    pic->pict_type = AV_PICTURE_TYPE_I;
+    y = (uint16_t*)pic->data[0] + slice_start * (pic->linesize[0] >> 1);
+    u = (uint16_t*)pic->data[1] + slice_start * (pic->linesize[1] >> 1);
+    v = (uint16_t*)pic->data[2] + slice_start * (pic->linesize[2] >> 1);
 
-    y = (uint16_t *)pic->data[0];
-    u = (uint16_t *)pic->data[1];
-    v = (uint16_t *)pic->data[2];
-
-    for (i = 0; i < avctx->height; i++) {
+    for (i = slice_start; i < avctx->height; i++) {
         for (j = 0; j < avctx->width; j++) {
             val = AV_RL32(src);
 
@@ -82,6 +89,34 @@ static int v410_decode_frame(AVCodecContext *avctx, void *data,
         v += pic->linesize[2] >> 1;
     }
 
+    return 0;
+}
+
+static int v410_decode_frame(AVCodecContext *avctx, void *data,
+                             int *got_frame, AVPacket *avpkt)
+{
+    ThreadData td;
+    AVFrame *pic = data;
+    uint8_t *src = avpkt->data;
+    int ret;
+    int thread_count = av_clip(avctx->thread_count, 1, MAX_SLICES);
+
+    td.stride = avctx->width * 4;
+    if (avpkt->size < 4 * avctx->height * avctx->width) {
+        av_log(avctx, AV_LOG_ERROR, "Insufficient input data.\n");
+        return AVERROR(EINVAL);
+    }
+
+    if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
+        return ret;
+
+    pic->key_frame = 1;
+    pic->pict_type = AV_PICTURE_TYPE_I;
+
+    td.buf = src;
+    td.frame = pic;
+    avctx->execute2(avctx, v410_decode_slice, &td, NULL, thread_count);
+
     *got_frame = 1;
 
     return avpkt->size;
@@ -94,5 +129,7 @@ AVCodec ff_v410_decoder = {
     .id           = AV_CODEC_ID_V410,
     .init         = v410_decode_init,
     .decode       = v410_decode_frame,
-    .capabilities = AV_CODEC_CAP_DR1,
+    .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SLICE_THREADS,
+    .caps_internal= FF_CODEC_CAP_INIT_THREADSAFE |
+                      FF_CODEC_CAP_INIT_CLEANUP,
 };
-- 
2.6.4