[FFmpeg-cvslog] avcodec/v4l2m2m: fix error handling during buffer init

[Jorge Ramirez-Ortiz]

ffmpeg | branch: master | Jorge Ramirez-Ortiz <jramirez at baylibre.com> | Sun May  6 19:56:30 2018 +0200| [da45ad48f9935a3264e9a6d85127dcaf0eee38b3] | committer: Aman Gupta

avcodec/v4l2m2m: fix error handling during buffer init

Signed-off-by: Jorge Ramirez-Ortiz <jramirez at baylibre.com>
Signed-off-by: Aman Gupta <aman at tmm1.net>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=da45ad48f9935a3264e9a6d85127dcaf0eee38b3
---

 libavcodec/v4l2_context.c | 19 ++++++++++++++++---
 libavcodec/v4l2_m2m_dec.c |  9 +++++++--
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/libavcodec/v4l2_context.c b/libavcodec/v4l2_context.c
index 3e180e46b1..c28d46d777 100644
--- a/libavcodec/v4l2_context.c
+++ b/libavcodec/v4l2_context.c
@@ -267,6 +267,12 @@ static V4L2Buffer* v4l2_dequeue_v4l2buf(V4L2Context *ctx, int timeout)
     /* if we are draining and there are no more capture buffers queued in the driver we are done */
     if (!V4L2_TYPE_IS_OUTPUT(ctx->type) && ctx_to_m2mctx(ctx)->draining) {
         for (i = 0; i < ctx->num_buffers; i++) {
+            /* capture buffer initialization happens during decode hence
+             * detection happens at runtime
+             */
+            if (!ctx->buffers)
+                break;
+
             if (ctx->buffers[i].status == V4L2BUF_IN_DRIVER)
                 goto start;
         }
@@ -698,9 +704,8 @@ int ff_v4l2_context_init(V4L2Context* ctx)
         ctx->buffers[i].context = ctx;
         ret = ff_v4l2_buffer_initialize(&ctx->buffers[i], i);
         if (ret < 0) {
-            av_log(logger(ctx), AV_LOG_ERROR, "%s buffer initialization (%s)\n", ctx->name, av_err2str(ret));
-            av_free(ctx->buffers);
-            return ret;
+            av_log(logger(ctx), AV_LOG_ERROR, "%s buffer[%d] initialization (%s)\n", ctx->name, i, av_err2str(ret));
+            goto error;
         }
     }
 
@@ -713,4 +718,12 @@ int ff_v4l2_context_init(V4L2Context* ctx)
         V4L2_TYPE_IS_MULTIPLANAR(ctx->type) ? ctx->format.fmt.pix_mp.plane_fmt[0].bytesperline : ctx->format.fmt.pix.bytesperline);
 
     return 0;
+
+error:
+    v4l2_release_buffers(ctx);
+
+    av_free(ctx->buffers);
+    ctx->buffers = NULL;
+
+    return ret;
 }
diff --git a/libavcodec/v4l2_m2m_dec.c b/libavcodec/v4l2_m2m_dec.c
index d0601f0e2f..6f31772f4c 100644
--- a/libavcodec/v4l2_m2m_dec.c
+++ b/libavcodec/v4l2_m2m_dec.c
@@ -86,8 +86,8 @@ static int v4l2_try_start(AVCodecContext *avctx)
     if (!capture->buffers) {
         ret = ff_v4l2_context_init(capture);
         if (ret) {
-            av_log(avctx, AV_LOG_DEBUG, "can't request output buffers\n");
-            return ret;
+            av_log(avctx, AV_LOG_ERROR, "can't request capture buffers\n");
+            return AVERROR(ENOMEM);
         }
     }
 
@@ -151,6 +151,11 @@ static int v4l2_receive_frame(AVCodecContext *avctx, AVFrame *frame)
         ret = v4l2_try_start(avctx);
         if (ret) {
             av_packet_unref(&avpkt);
+
+            /* cant recover */
+            if (ret == AVERROR(ENOMEM))
+                return ret;
+
             return 0;
         }
     }