[FFmpeg-devel] [PATCH, v2] lavc/vaapi_encode: grow packet if vaMapBuffer returns multiple buffers

[Linjie Fu]

It seems that VA_CODED_BUF_STATUS_SINGLE_NALU allows driver to map
buffer for each slice.

Currently, assigning new buffer for pkt when multiple buffer returns
from vaMapBuffer will cover the previous encoded pkt data and lead
to encode issues.

Iterate through the buf_list first to find out the total buffer size
needed for the pkt, allocate the whole pkt to avoid repeated reallocation
and memcpy, then copy data from each buf to pkt.

Signed-off-by: Linjie Fu <linjie.fu at intel.com>
---
[v2]: allocate the whole pkt to avoid repeated reallocation
and memcpy

 libavcodec/vaapi_encode.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/libavcodec/vaapi_encode.c b/libavcodec/vaapi_encode.c
index 2dda451..9c9e5dd 100644
--- a/libavcodec/vaapi_encode.c
+++ b/libavcodec/vaapi_encode.c
@@ -489,6 +489,8 @@ static int vaapi_encode_output(AVCodecContext *avctx,
     VAAPIEncodeContext *ctx = avctx->priv_data;
     VACodedBufferSegment *buf_list, *buf;
     VAStatus vas;
+    int total_size = 0;
+    uint8_t *ptr;
     int err;
 
     err = vaapi_encode_wait(avctx, pic);
@@ -505,15 +507,21 @@ static int vaapi_encode_output(AVCodecContext *avctx,
         goto fail;
     }
 
+    for (buf = buf_list; buf; buf = buf->next)
+        total_size += buf->size;
+
+    err = av_new_packet(pkt, total_size);
+    ptr = pkt->data;
+
+    if (err < 0)
+        goto fail_mapped;
+
     for (buf = buf_list; buf; buf = buf->next) {
         av_log(avctx, AV_LOG_DEBUG, "Output buffer: %u bytes "
                "(status %08x).\n", buf->size, buf->status);
 
-        err = av_new_packet(pkt, buf->size);
-        if (err < 0)
-            goto fail_mapped;
-
-        memcpy(pkt->data, buf->buf, buf->size);
+        memcpy(ptr, buf->buf, buf->size);
+        ptr += buf->size;
     }
 
     if (pic->type == PICTURE_TYPE_IDR)
-- 
2.7.4