h264section: set min bit rate on target file size

app/codec/encoder.cpp

@@ -45,6 +45,7 @@ void Encoder::WriteAudio(AudioParams pcm_info, const QString &pcm_filename)
 EncodingParams::EncodingParams() :
   video_enabled_(false),
   video_bit_rate_(0),
+  video_min_bit_rate_(0),
   video_max_bit_rate_(0),
   video_buffer_size_(0),
   video_threads_(0),
@@ -82,6 +83,11 @@ void EncodingParams::set_video_bit_rate(const int64_t &rate)
   video_bit_rate_ = rate;
 }
 
+void EncodingParams::set_video_min_bit_rate(const int64_t &rate)
+{
+  video_min_bit_rate_ = rate;
+}
+
 void EncodingParams::set_video_max_bit_rate(const int64_t &rate)
 {
   video_max_bit_rate_ = rate;
@@ -132,6 +138,11 @@ const int64_t &EncodingParams::video_bit_rate() const
   return video_bit_rate_;
 }
 
+const int64_t &EncodingParams::video_min_bit_rate() const
+{
+  return video_min_bit_rate_;
+}
+
 const int64_t &EncodingParams::video_max_bit_rate() const
 {
   return video_max_bit_rate_;
@@ -193,6 +204,7 @@ void EncodingParams::Save(QXmlStreamWriter *writer) const
     writer->writeTextElement(QStringLiteral("timebase"), video_params_.time_base().toString());
     writer->writeTextElement(QStringLiteral("divider"), QString::number(video_params_.divider()));
     writer->writeTextElement(QStringLiteral("bitrate"), QString::number(video_bit_rate_));
+    writer->writeTextElement(QStringLiteral("minbitrate"), QString::number(video_max_bit_rate_));
     writer->writeTextElement(QStringLiteral("maxbitrate"), QString::number(video_max_bit_rate_));
     writer->writeTextElement(QStringLiteral("bufsize"), QString::number(video_buffer_size_));
     writer->writeTextElement(QStringLiteral("threads"), QString::number(video_threads_));

app/codec/encoder.h

@@ -48,6 +48,7 @@ public:
 
   void set_video_option(const QString& key, const QString& value);
   void set_video_bit_rate(const int64_t& rate);
+  void set_video_min_bit_rate(const int64_t& rate);
   void set_video_max_bit_rate(const int64_t& rate);
   void set_video_buffer_size(const int64_t& sz);
   void set_video_threads(const int& threads);
@@ -60,6 +61,7 @@ public:
   const VideoParams& video_params() const;
   const QHash<QString, QString>& video_opts() const;
   const int64_t& video_bit_rate() const;
+  const int64_t& video_min_bit_rate() const;
   const int64_t& video_max_bit_rate() const;
   const int64_t& video_buffer_size() const;
   const int& video_threads() const;
@@ -92,6 +94,7 @@ private:
   VideoParams video_params_;
   QHash<QString, QString> video_opts_;
   int64_t video_bit_rate_;
+  int64_t video_min_bit_rate_;
   int64_t video_max_bit_rate_;
   int64_t video_buffer_size_;
   int video_threads_;

app/codec/ffmpeg/ffmpegencoder.cpp

@@ -517,6 +517,10 @@ bool FFmpegEncoder::InitializeStream(AVMediaType type, AVStream** stream_ptr, AV
         codec_ctx->bit_rate = params().video_bit_rate();
       }
 
+      if (params().video_min_bit_rate() > 0) {
+        codec_ctx->rc_min_rate = params().video_min_bit_rate();
+      }
+
       if (params().video_max_bit_rate() > 0) {
         codec_ctx->rc_max_rate = params().video_max_bit_rate();
       }

app/dialog/export/codec/h264section.cpp

@@ -82,15 +82,17 @@ void H264Section::AddOpts(EncodingParams *params)
 
   } else {
 
-    int64_t target_rate, max_rate;
+    int64_t target_rate, max_rate, min_rate;
 
     if (method == kTargetBitRate) {
       // Use user-supplied values for the bit rate
       target_rate = bitrate_section_->GetTargetBitRate();
+      min_rate = 0;
       max_rate = bitrate_section_->GetMaximumBitRate();
     } else {
       // Calculate the bit rate from the file size divided by the sequence length in seconds (bits per second)
       target_rate = qRound64(static_cast<double>(filesize_section_->GetFileSize()) / params->GetExportLength().toDouble());
+      min_rate = target_rate;
       max_rate = target_rate;
     }
 
@@ -98,6 +100,7 @@ void H264Section::AddOpts(EncodingParams *params)
     params->set_video_option(QStringLiteral("crf"), QStringLiteral("-1"));
 
     params->set_video_bit_rate(target_rate);
+    params->set_video_min_bit_rate(min_rate);
     params->set_video_max_bit_rate(max_rate);
     params->set_video_buffer_size(2000000);