Make QtAV build with newer versions of FFmpeg

Some defines changed their name in newer versions of FFmpeg, this
patch uses preprocessor instructions in AVCompat.h to use the
correct define names. Also filter names retrieved by
'avfilter_get_by_name' should be used as const variables in
libavfilter versions starting at 7.0.0.

src/AVMuxer.cpp

@@ -124,7 +124,7 @@ AVStream *AVMuxer::Private::addStream(AVFormatContext* ctx, const QString &codec
     c->time_base = s->time_base;
     /* Some formats want stream headers to be separate. */
     if (ctx->oformat->flags & AVFMT_GLOBALHEADER)
-        c->flags |= CODEC_FLAG_GLOBAL_HEADER;
+        c->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
     // expose avctx to encoder and set properties in encoder?
     // list codecs for a given format in ui
     return s;

src/QtAV/private/AVCompat.h

@@ -456,3 +456,15 @@ const char *get_codec_long_name(AVCodecID id);
      } } while(0)
 
 #endif //QTAV_COMPAT_H
+
+#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(56,33,0)
+#define AV_CODEC_FLAG_GLOBAL_HEADER CODEC_FLAG_GLOBAL_HEADER
+#endif
+
+#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(56,56,100)
+#define AV_INPUT_BUFFER_MIN_SIZE FF_MIN_BUFFER_SIZE
+#endif
+
+#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(56,56,100)
+#define AV_INPUT_BUFFER_PADDING_SIZE FF_INPUT_BUFFER_PADDING_SIZE
+#endif

src/codec/audio/AudioEncoderFFmpeg.cpp

@@ -151,8 +151,8 @@ bool AudioEncoderFFmpegPrivate::open()
     } else {
         buffer_size = frame_size*format_used.bytesPerSample()*format_used.channels()*2+200;
     }
-    if (buffer_size < FF_MIN_BUFFER_SIZE)
-        buffer_size = FF_MIN_BUFFER_SIZE;
+    if (buffer_size < AV_INPUT_BUFFER_MIN_SIZE)
+        buffer_size = AV_INPUT_BUFFER_MIN_SIZE;
     buffer.resize(buffer_size);
     return true;
 }

src/codec/video/VideoEncoderFFmpeg.cpp

@@ -245,7 +245,7 @@ bool VideoEncoderFFmpegPrivate::open()
     applyOptionsForContext();
     AV_ENSURE_OK(avcodec_open2(avctx, codec, &dict), false);
     // from mpv ao_lavc
-    const int buffer_size = qMax<int>(qMax<int>(width*height*6+200, FF_MIN_BUFFER_SIZE), sizeof(AVPicture));//??
+    const int buffer_size = qMax<int>(qMax<int>(width*height*6+200, AV_INPUT_BUFFER_MIN_SIZE), sizeof(AVPicture));//??
     buffer.resize(buffer_size);
     return true;
 }

src/filter/LibAVFilter.cpp

@@ -120,14 +120,20 @@ class LibAVFilter::Private
         // pixel_aspect==sar, pixel_aspect is more compatible
         QString buffersrc_args = args;
         qDebug("buffersrc_args=%s", buffersrc_args.toUtf8().constData());
-        AVFilter *buffersrc  = avfilter_get_by_name(video ? "buffer" : "abuffer");
+#if LIBAVFILTER_VERSION_INT >= AV_VERSION_INT(7,0,0)
+        const
+#endif
+        AVFilter *buffersrc = avfilter_get_by_name(video ? "buffer" : "abuffer");
         Q_ASSERT(buffersrc);
         AV_ENSURE_OK(avfilter_graph_create_filter(&in_filter_ctx,
                                                buffersrc,
                                                "in", buffersrc_args.toUtf8().constData(), NULL,
                                                filter_graph)
                      , false);
         /* buffer video sink: to terminate the filter chain. */
+#if LIBAVFILTER_VERSION_INT >= AV_VERSION_INT(7,0,0)
+        const
+#endif
         AVFilter *buffersink = avfilter_get_by_name(video ? "buffersink" : "abuffersink");
         Q_ASSERT(buffersink);
         AV_ENSURE_OK(avfilter_graph_create_filter(&out_filter_ctx, buffersink, "out",

src/subtitle/SubtitleProcessorFFmpeg.cpp

@@ -249,7 +249,7 @@ bool SubtitleProcessorFFmpeg::processHeader(const QByteArray &codec, const QByte
     codec_ctx->time_base.den = 1000;
     if (!data.isEmpty()) {
         av_free(codec_ctx->extradata);
-        codec_ctx->extradata = (uint8_t*)av_mallocz(data.size() + FF_INPUT_BUFFER_PADDING_SIZE);
+        codec_ctx->extradata = (uint8_t*)av_mallocz(data.size() + AV_INPUT_BUFFER_PADDING_SIZE);
         if (!codec_ctx->extradata)
             return false;
         codec_ctx->extradata_size = data.size();