fix old avformat iterate(gcc)

Author: wang-bin

src/AVDemuxer.cpp

@@ -357,11 +357,12 @@ static void getFFmpegInputFormats(QStringList* formats, QStringList* extensions)
     static QStringList fmts;
     if (exts.isEmpty() && fmts.isEmpty()) {
         QStringList e, f;
-        const AVInputFormat *i = NULL;
 #if AVFORMAT_STATIC_REGISTER
+        const AVInputFormat *i = NULL;
         void* it = NULL;
         while ((i = av_demuxer_iterate(&it))) {
 #else
+        AVInputFormat *i = NULL;
         av_register_all(); // MUST register all input/output formats
         while ((i = av_iformat_next(i))) {
 #endif

src/AVMuxer.cpp

@@ -189,12 +189,13 @@ static void getFFmpegOutputFormats(QStringList* formats, QStringList* extensions
     static QStringList fmts;
     if (exts.isEmpty() && fmts.isEmpty()) {
         QStringList e, f;
-        const AVOutputFormat *o = NULL;
 #if AVFORMAT_STATIC_REGISTER
+        const AVOutputFormat *o = NULL;
         void* it = NULL;
         while ((o = av_muxer_iterate(&it))) {
 #else
         av_register_all(); // MUST register all input/output formats
+        AVOutputFormat *o = NULL;
         while ((o = av_oformat_next(o))) {
 #endif
             if (o->extensions)

src/QtAV_Global.cpp

@@ -275,11 +275,12 @@ QString avformatOptions()
     void* obj =  const_cast<void*>(reinterpret_cast<const void*>(avformat_get_class()));
     opts = Internal::optionsToString((void*)&obj);
     opts.append(ushort('\n'));
-    const AVInputFormat *i = NULL;
 #if AVFORMAT_STATIC_REGISTER
+    const AVInputFormat *i = NULL;
     void* it = NULL;
     while ((i = av_demuxer_iterate(&it))) {
 #else
+    AVInputFormat *i = NULL;
     av_register_all(); // MUST register all input/output formats
     while ((i = av_iformat_next(i))) {
 #endif
@@ -290,12 +291,13 @@ QString avformatOptions()
                     .arg(QLatin1String(i->name))
                     .arg(opt));
     }
-    const AVOutputFormat *o = NULL;
 #if AVFORMAT_STATIC_REGISTER
+    const AVOutputFormat *o = NULL;
     it = NULL;
     while ((o = av_muxer_iterate(&it))) {
 #else
     av_register_all(); // MUST register all input/output formats
+    AVOutputFormat *o = NULL;
     while ((o = av_oformat_next(o))) {
 #endif
         QString opt(Internal::optionsToString((void*)&o->priv_class).trimmed());

src/subtitle/SubtitleProcessorFFmpeg.cpp

@@ -91,12 +91,13 @@ QStringList ffmpeg_supported_sub_extensions_by_codec()
         if (c->type != AVMEDIA_TYPE_SUBTITLE)
             continue;
         qDebug("sub codec: %s", c->name);
-        const AVInputFormat *i = NULL;
 #if AVFORMAT_STATIC_REGISTER
+        const AVInputFormat *i = NULL;
         void* it2 = NULL;
         while ((i = av_demuxer_iterate(&it2))) {
 #else
         av_register_all(); // MUST register all input/output formats
+        AVInputFormat *i = NULL;
         while ((i = av_iformat_next(i))) {
 #endif
             if (!strcmp(i->name, c->name)) {
@@ -121,12 +122,13 @@ QStringList ffmpeg_supported_sub_extensions_by_codec()
 QStringList ffmpeg_supported_sub_extensions()
 {
     QStringList exts;
-    const AVInputFormat *i = NULL;
 #if AVFORMAT_STATIC_REGISTER
+    const AVInputFormat *i = NULL;
     void* it = NULL;
     while ((i = av_demuxer_iterate(&it))) {
 #else
     av_register_all(); // MUST register all input/output formats
+    AVInputFormat *i = NULL;
     while ((i = av_iformat_next(i))) {
 #endif
         // strstr parameters can not be null