From: Dimitry Ishenko <dimitry.ishenko@gmail.com>
Date: Sun, 26 Jun 2016 13:38:24 +0000 (-0400)
Subject: [ffmpeg_producer] Add relative and "from end" seeking
X-Git-Tag: 2.1.0_Beta1~40^2
X-Git-Url: https://git.sesse.net/?p=casparcg;a=commitdiff_plain;h=6284495c607f75d43cbb5238f714645967fc1679

[ffmpeg_producer] Add relative and "from end" seeking
---

diff --git a/modules/ffmpeg/producer/ffmpeg_producer.cpp b/modules/ffmpeg/producer/ffmpeg_producer.cpp
index a77994896..634e4dd62 100644
--- a/modules/ffmpeg/producer/ffmpeg_producer.cpp
+++ b/modules/ffmpeg/producer/ffmpeg_producer.cpp
@@ -391,7 +391,7 @@ public:
 	std::future<std::wstring> call(const std::vector<std::wstring>& params) override
 	{
 		static const boost::wregex loop_exp(LR"(LOOP\s*(?<VALUE>\d?)?)", boost::regex::icase);
-		static const boost::wregex seek_exp(LR"(SEEK\s+(?<VALUE>\d+))", boost::regex::icase);
+		static const boost::wregex seek_exp(LR"(SEEK\s+(?<VALUE>(\+|-)?\d+)(\s+(?<WHENCE>REL|END))?)", boost::regex::icase);
 		static const boost::wregex length_exp(LR"(LENGTH\s+(?<VALUE>\d+)?)", boost::regex::icase);
 		static const boost::wregex start_exp(LR"(START\\s+(?<VALUE>\\d+)?)", boost::regex::icase);
 
@@ -409,8 +409,19 @@ public:
 		}
 		else if(boost::regex_match(param, what, seek_exp))
 		{
-			auto value = what["VALUE"].str();
-			input_.seek(boost::lexical_cast<uint32_t>(value));
+			auto value = boost::lexical_cast<uint32_t>(what["VALUE"].str());
+			auto whence = what["WHENCE"].str();
+
+			if(boost::iequals(whence, L"REL"))
+			{
+				value = file_frame_number() + value;
+			}
+			else if(boost::iequals(whence, L"END"))
+			{
+				value = file_nb_frames() - value;
+			}
+
+			input_.seek(value);
 		}
 		else if(boost::regex_match(param, what, length_exp))
 		{