[FFmpeg-devel] [PATCH v1 2/2] avcodec/v4l2_buffer: export v4l2 buffer dma-buf

[Ming Qian]

Signed-off-by: Ming Qian <ming.qian at nxp.com>
---
 libavcodec/v4l2_buffers.c | 14 ++++++++++++++
 libavcodec/v4l2_buffers.h |  1 +
 libavcodec/v4l2_context.c |  4 ++++
 3 files changed, 19 insertions(+)

diff --git a/libavcodec/v4l2_buffers.c b/libavcodec/v4l2_buffers.c
index 4b2679eb3814..efa42f4c58ea 100644
--- a/libavcodec/v4l2_buffers.c
+++ b/libavcodec/v4l2_buffers.c
@@ -21,6 +21,9 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
 #include <linux/videodev2.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
@@ -267,6 +270,8 @@ static int v4l2_buf_to_bufref(V4L2Buffer *in, int plane, AVBufferRef **buf)
     if (!*buf)
         return AVERROR(ENOMEM);
 
+    if (in->plane_info[plane].dmafd >= 0)
+        av_buffer_set_dma_buf(*buf, in->plane_info[plane].dmafd);
     ret = v4l2_buf_increase_ref(in);
     if (ret)
         av_buffer_unref(buf);
@@ -494,6 +499,7 @@ int ff_v4l2_buffer_avpkt_to_buf(const AVPacket *pkt, V4L2Buffer *out)
 int ff_v4l2_buffer_initialize(V4L2Buffer* avbuf, int index)
 {
     V4L2Context *ctx = avbuf->context;
+    struct v4l2_exportbuffer exp;
     int ret, i;
 
     avbuf->buf.memory = V4L2_MEMORY_MMAP;
@@ -539,6 +545,14 @@ int ff_v4l2_buffer_initialize(V4L2Buffer* avbuf, int index)
 
         if (avbuf->plane_info[i].mm_addr == MAP_FAILED)
             return AVERROR(ENOMEM);
+
+        exp.type = ctx->type;
+        exp.index = avbuf->buf.index;
+        exp.plane = i;
+        exp.fd = -1;
+        exp.flags = O_CLOEXEC | O_RDWR;
+        ioctl(buf_to_m2mctx(avbuf)->fd, VIDIOC_EXPBUF, &exp);
+        avbuf->plane_info[i].dmafd = exp.fd;
     }
 
     avbuf->status = V4L2BUF_AVAILABLE;
diff --git a/libavcodec/v4l2_buffers.h b/libavcodec/v4l2_buffers.h
index 3d2ff1b9a5d7..74550544e0eb 100644
--- a/libavcodec/v4l2_buffers.h
+++ b/libavcodec/v4l2_buffers.h
@@ -55,6 +55,7 @@ typedef struct V4L2Buffer {
         int bytesperline;
         void * mm_addr;
         size_t length;
+        int dmafd;
     } plane_info[VIDEO_MAX_PLANES];
 
     int num_planes;
diff --git a/libavcodec/v4l2_context.c b/libavcodec/v4l2_context.c
index b08f0015c2e5..f0406194293d 100644
--- a/libavcodec/v4l2_context.c
+++ b/libavcodec/v4l2_context.c
@@ -453,6 +453,10 @@ static int v4l2_release_buffers(V4L2Context* ctx)
             if (p->mm_addr && p->length)
                 if (munmap(p->mm_addr, p->length) < 0)
                     av_log(logger(ctx), AV_LOG_ERROR, "%s unmap plane (%s))\n", ctx->name, av_err2str(AVERROR(errno)));
+            if (p->dmafd >= 0) {
+                close(p->dmafd);
+                p->dmafd = -1;
+            }
         }
     }
 
-- 
2.33.0