GUACAMOLE-465: resolved issues brought up in PR159 and added compatibility with recent versions of libavcodec

src/guacenc/ffmpeg-compat.c

@@ -55,7 +55,7 @@ static int guacenc_write_packet(guacenc_video* video, void* data, int size) {
 
 #if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(54,1,0)
     AVPacket pkt;
-    /* have to create a packet around the encoded data we have */
+    /* Have to create a packet around the encoded data we have */
     av_init_packet(&pkt);
 
     if (video->context->coded_frame->pts != AV_NOPTS_VALUE) {
@@ -207,9 +207,7 @@ AVCodecContext* guacenc_build_avcodeccontext(AVStream* stream, AVCodec* codec,
     stream->codec->qmin = qmin;
     stream->codec->pix_fmt = pix_fmt;
     stream->codec->time_base = time_base;
-#if LIBAVFORMAT_VERSION_INT < AV_VERSION_INT(55, 44, 100)
-    stream->codec->time_base = time_base;
-#else
+#if LIBAVFORMAT_VERSION_INT >= AV_VERSION_INT(55, 44, 100)
     stream->time_base = time_base;
 #endif
     return stream->codec;
@@ -234,12 +232,10 @@ AVCodecContext* guacenc_build_avcodeccontext(AVStream* stream, AVCodec* codec,
 int guacenc_open_avcodec(AVCodecContext *avcodec_context,
         AVCodec *codec, AVDictionary **options,
         AVStream* stream) {
-    int ret = 0;
-    ret = avcodec_open2(avcodec_context, codec, options);
+    int ret = avcodec_open2(avcodec_context, codec, options);
 #if LIBAVFORMAT_VERSION_INT >= AV_VERSION_INT(57, 33, 100)
-    int codecpar_ret = 0;
     /* copy stream parameters to the muxer */
-    codecpar_ret = avcodec_parameters_from_context(stream->codecpar,
+    int codecpar_ret = avcodec_parameters_from_context(stream->codecpar,
             avcodec_context);
     if (codecpar_ret < 0) {
         return codecpar_ret;

src/guacenc/ffmpeg-compat.h

@@ -52,6 +52,16 @@
 #define av_packet_unref av_free_packet
 #endif
 
+/* For libavcodec <= 56.41.100: Global header flag didn't have AV_ prefix.
+ * Guacenc defines its own flag here to avoid conflicts with libavcodec
+ * macros.
+ */
+#if LIBAVCODEC_VERSION_INT <= AV_VERSION_INT(56,41,100)
+#define GUACENC_FLAG_GLOBAL_HEADER CODEC_FLAG_GLOBAL_HEADER
+#else
+#define GUACENC_FLAG_GLOBAL_HEADER AV_CODEC_FLAG_GLOBAL_HEADER
+#endif
+
 /* For libavutil < 51.42.0: AV_PIX_FMT_* was PIX_FMT_* */
 #if LIBAVUTIL_VERSION_INT < AV_VERSION_INT(51,42,0)
 #define AV_PIX_FMT_RGB32 PIX_FMT_RGB32
@@ -80,7 +90,9 @@ int guacenc_avcodec_encode_video(guacenc_video* video, AVFrame* frame);
 
 /**
  * Creates and sets up the AVCodecContext for the appropriate version
- * of libavformat installed
+ * of libavformat installed. The AVCodecContext will be built, but
+ * the AVStream will also be affected by having its time_base field
+ * set to the value passed into this function.
  *
  * @param stream
  *     The open AVStream
@@ -112,6 +124,9 @@ int guacenc_avcodec_encode_video(guacenc_video* video, AVFrame* frame);
  * @param time_base
  *     The target time base for the encoded video
  *
+ * @return
+ *     The pointer to the configured AVCodecContext
+ *
  */
 AVCodecContext* guacenc_build_avcodeccontext(AVStream* stream, AVCodec* codec,
         int bitrate, int width, int height, int gop_size, int qmax, int qmin,
@@ -125,19 +140,25 @@ AVCodecContext* guacenc_build_avcodeccontext(AVStream* stream, AVCodec* codec,
  * So this wrapper handles that. Otherwise, it's the
  * same as avcodec_open2().
  *
- * @param avcodec_context The context to initialize.
- * @param codec The codec to open this context for. If a non-NULL codec has
- *              been previously passed to avcodec_alloc_context3() or
- *              for this context, then this parameter MUST be either NULL or
- *              equal to the previously passed codec.
- * @param options A dictionary filled with AVCodecContext and codec-private
- *                options. On return this object will be filled with options
- *                that were not found.
- * @param stream The stream for the codec context.
- *               Only used in libavformat >= 57.33.100. Can be NULL in
- *               lower versions
+ * @param avcodec_context
+ *     The context to initialize.
  *
- * @return zero on success, a negative value on error
+ * @param codec
+ *     The codec to open this context for. If a non-NULL codec has
+ *     been previously passed to avcodec_alloc_context3() or
+ *     for this context, then this parameter MUST be either NULL or
+ *     equal to the previously passed codec.
+ *
+ * @param options
+ *     A dictionary filled with AVCodecContext and codec-private
+ *     options. On return this object will be filled with options
+ *     that were not found.
+ *
+ * @param stream
+ *     The stream for the codec context.
+ *
+ * @return
+ *     Zero on success, a negative value on error
  */
 int guacenc_open_avcodec(AVCodecContext *avcodec_context,
         AVCodec *codec, AVDictionary **options,

src/guacenc/guacenc.c

@@ -81,8 +81,9 @@ int main(int argc, char* argv[]) {
     avcodec_register_all();
 #endif
 
-    /* Prepare libavformat */
+#if LIBAVFORMAT_VERSION_INT < AV_VERSION_INT(58, 9, 100)
     av_register_all();
+#endif
 
     /* Track number of overall failures */
     int total_files = argc - optind;

src/guacenc/video.c

@@ -91,9 +91,9 @@ guacenc_video* guacenc_video_alloc(const char* path, const char* codec_name,
         goto fail_context;
     }
 
-    //if format needs global headers, write them
+    /* If format needs global headers, write them */
     if (container_format_context->oformat->flags & AVFMT_GLOBALHEADER) {
-        avcodec_context->flags |= CODEC_FLAG_GLOBAL_HEADER;
+        avcodec_context->flags |= GUACENC_FLAG_GLOBAL_HEADER;
     }
 
     /* Open codec for use */

src/guacenc/video.h

@@ -51,7 +51,8 @@ typedef struct guacenc_video {
 
     /**
      * AVStream for video output.
-     * Persists via the AVFormatContext.
+     * Frames sent to this stream are written into
+     * the output file in the specified container format.
      */
     AVStream* output_stream;