From 17df235c4e1a74bf29c4604fae49a6876fd2b87d Mon Sep 17 00:00:00 2001
From: Michael Jumper <mike.jumper@guac-dev.org>
Date: Thu, 10 Mar 2016 18:29:03 -0800
Subject: [PATCH] GUAC-236: Actually open and init codec. Replace PNG output
 with stub.

---
 src/guacenc/video.c | 53 +++++++++++++++++++++++++++++++++++----------
 src/guacenc/video.h |  7 ++++++
 2 files changed, 48 insertions(+), 12 deletions(-)

diff --git a/src/guacenc/video.c b/src/guacenc/video.c
index e7a4dfd3..f4fd1fcd 100644
--- a/src/guacenc/video.c
+++ b/src/guacenc/video.c
@@ -36,19 +36,47 @@
 guacenc_video* guacenc_video_alloc(const char* path, const char* codec_name,
         int width, int height, int framerate, int bitrate) {
 
-    /* Allocate video structure */
-    guacenc_video* video = malloc(sizeof(guacenc_video));
-    if (video == NULL)
-        return NULL;
-
+    /* Pull codec based on name */
     AVCodec* codec = avcodec_find_encoder_by_name(codec_name);
     if (codec == NULL) {
-        guacenc_log(GUAC_LOG_ERROR, "Failed to locate codec: \"%s\"",
+        guacenc_log(GUAC_LOG_ERROR, "Failed to locate codec \"%s\".",
                 codec_name);
         return NULL;
     }
 
+    /* Retrieve encoding context */
+    AVCodecContext* context = avcodec_alloc_context3(codec);
+    if (context == NULL) {
+        guacenc_log(GUAC_LOG_ERROR, "Failed to allocate context for "
+                "codec \"%s\".", codec_name);
+        return NULL;
+    }
+
+    /* Init context with encoding parameters */
+    context->bit_rate = bitrate;
+    context->width = width;
+    context->height = height;
+    context->time_base = (AVRational) { 1, framerate };
+    context->gop_size = 10;
+    context->max_b_frames = 1;
+    context->pix_fmt = AV_PIX_FMT_YUV420P;
+
+    /* Open codec for use */
+    if (avcodec_open2(context, codec, NULL) < 0) {
+        guacenc_log(GUAC_LOG_ERROR, "Failed to open codec \"%s\".", codec_name);
+        avcodec_free_context(&context);
+        return NULL;
+    }
+
+    /* Allocate video structure */
+    guacenc_video* video = malloc(sizeof(guacenc_video));
+    if (video == NULL) {
+        avcodec_free_context(&context);
+        return NULL;
+    }
+
     /* Init properties of video */
+    video->context = context;
     video->width = width;
     video->height = height;
     video->frame_duration = 1000 / framerate;
@@ -81,12 +109,9 @@ static int guacenc_video_flush_frame(guacenc_video* video) {
     if (buffer == NULL)
         return 0;
 
-    /* STUB: Write frame as PNG */
-    char filename[256];
-    sprintf(filename, "frame-%012" PRId64 ".png", video->current_time);
-    cairo_surface_t* surface = buffer->surface;
-    if (surface != NULL)
-        cairo_surface_write_to_png(surface, filename);
+    /* STUB: Write frame to video */
+    guacenc_log(GUAC_LOG_DEBUG, "Writing frame @ %" PRId64 "ms",
+            video->current_time);
 
     /* Update internal timestamp */
     video->current_time += video->frame_duration;
@@ -135,6 +160,10 @@ int guacenc_video_free(guacenc_video* video) {
     /* Write final frame */
     guacenc_video_flush_frame(video);
 
+    /* Clean up encoding context */
+    avcodec_close(video->context);
+    avcodec_free_context(&(video->context));
+
     free(video);
     return 0;
 
diff --git a/src/guacenc/video.h b/src/guacenc/video.h
index b5a27498..21787bbc 100644
--- a/src/guacenc/video.h
+++ b/src/guacenc/video.h
@@ -27,6 +27,7 @@
 #include "buffer.h"
 
 #include <guacamole/timestamp.h>
+#include <libavcodec/avcodec.h>
 
 /**
  * A video which is actively being encoded. Frames can be added to the video
@@ -35,6 +36,12 @@
  */
 typedef struct guacenc_video {
 
+    /**
+     * The open encoding context from libavcodec, created for the codec
+     * specified when this guacenc_video was created.
+     */
+    AVCodecContext* context;
+
     /**
      * The width of the video, in pixels.
      */