From 6c628cfe720a3508f59862fba112692cc6bc3045 Mon Sep 17 00:00:00 2001
From: Kamil Trzcinski <ayufan@ayufan.eu>
Date: Mon, 4 Apr 2022 22:52:31 +0200
Subject: [PATCH] Fix buffer re-use on short streaming

---
 buffer.c      |  4 ----
 buffer_list.c | 22 +++++++++++++++++++++-
 http_h264.c   |  7 ++++++-
 http_jpeg.c   | 21 +++++++++++++++++----
 4 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/buffer.c b/buffer.c
index dd57b4c..12e42c7 100644
--- a/buffer.c
+++ b/buffer.c
@@ -53,10 +53,6 @@ buffer_t *buffer_open(const char *name, buffer_list_t *buf_list, int index) {
     buf->dma_fd = v4l2_exp.fd;
   }
 
-  if (buf_list->do_capture) {
-    buffer_consumed(buf);
-  }
-
   return buf;
 
 error:
diff --git a/buffer_list.c b/buffer_list.c
index 85f5a67..7e061e4 100644
--- a/buffer_list.c
+++ b/buffer_list.c
@@ -167,8 +167,28 @@ int buffer_list_stream(buffer_list_t *buf_list, bool do_on)
   E_XIOCTL(buf_list, buf_list->device->fd, do_on ? VIDIOC_STREAMON : VIDIOC_STREAMOFF, &type, "Cannot set streaming state");
   buf_list->streaming = do_on;
 
-  E_LOG_DEBUG(buf_list, "Streaming %s...", do_on ? "started" : "stopped");
+  for (int i = 0; i < buf_list->nbufs; i++) {
+    buffer_t *buf = buf_list->bufs[i];
 
+    // dequeue buffers (when stream off)
+    if (buf->enqueued) {
+      if (buf->mmap_source) {
+        buf->mmap_source->used = 0;
+        buffer_consumed(buf->mmap_source);
+        buf->mmap_source = NULL;
+      }
+
+      buf->enqueued = false;
+      buf->mmap_reflinks = 1;
+    }
+
+    // re-enqueue buffers on stream start
+    if (buf_list->streaming && buf_list->do_capture && !buf->enqueued && buf->mmap_reflinks == 1) {
+      buffer_consumed(buf);
+    }
+  }
+
+  E_LOG_DEBUG(buf_list, "Streaming %s...", do_on ? "started" : "stopped");
   return 0;
 
 error:
diff --git a/http_h264.c b/http_h264.c
index efe0ae6..b5e2e8a 100644
--- a/http_h264.c
+++ b/http_h264.c
@@ -32,10 +32,12 @@ void http_video(http_worker_t *worker, FILE *stream)
   int counter = 0;
   fprintf(stream, VIDEO_HEADER);
 
+  buffer_lock_use(&http_h264, 1);
+
   while (!feof(stream)) {
     buffer_t *buf = buffer_lock_get(&http_h264, 3, &counter);
     if (!buf) {
-      return;
+      goto error;
     }
 
     if (buf->v4l2_buffer.flags & V4L2_BUF_FLAG_KEYFRAME) {
@@ -51,4 +53,7 @@ void http_video(http_worker_t *worker, FILE *stream)
     }
     buffer_consumed(buf);
   }
+
+error:
+  buffer_lock_use(&http_h264, -1);
 }
diff --git a/http_jpeg.c b/http_jpeg.c
index 8309575..cd166e7 100644
--- a/http_jpeg.c
+++ b/http_jpeg.c
@@ -42,6 +42,7 @@ void http_jpeg_capture(buffer_t *buf)
 void http_snapshot(http_worker_t *worker, FILE *stream)
 {
   int counter = 0;
+  buffer_lock_use(&http_jpeg, 1);
   buffer_t *buf = buffer_lock_get(&http_jpeg, 1, &counter);
 
   if (!buf) {
@@ -56,25 +57,37 @@ void http_snapshot(http_worker_t *worker, FILE *stream)
   fprintf(stream, "\r\n");
   fwrite(buf->start, buf->used, 1, stream);
   buffer_consumed(buf);
+error:
+  buffer_lock_use(&http_jpeg, -1);
 }
 
 void http_stream(http_worker_t *worker, FILE *stream)
 {
   int counter = 0;
   fprintf(stream, STREAM_HEADER);
+  buffer_lock_use(&http_jpeg, 1);
 
   while (!feof(stream)) {
     buffer_t *buf = buffer_lock_get(&http_jpeg, 3, &counter);
 
     if (!buf) {
       fprintf(stream, STREAM_ERROR, -1, "No frames.");
-      return;
+      goto error;
     }
 
-    fprintf(stream, STREAM_PART, buf->used);
-    fwrite(buf->start, buf->used, 1, stream);
-    fprintf(stream, STREAM_BOUNDARY);
+    if (!fprintf(stream, STREAM_PART, buf->used)) {
+      goto error;
+    }
+    if (!fwrite(buf->start, buf->used, 1, stream)) {
+      goto error;
+    }
+    if (!fprintf(stream, STREAM_BOUNDARY)) {
+      goto error;
+    }
 
     buffer_consumed(buf);
   }
+
+error:
+  buffer_lock_use(&http_jpeg, -1);
 }