From a0cc3db59138fd9bd35f792caeaff27e286f76d5 Mon Sep 17 00:00:00 2001
From: Martin Pulec <pulec@cesnet.cz>
Date: Tue, 22 Jan 2019 17:19:14 +0100
Subject: [PATCH] Transmit: correctly split packets

Correctly split packets for different pixel formats - previously there
was preset 48 B boundary which was least common multiple for then
present pixel formats (v210 has 16, RGB 3). However, R12L is not covered
since it uses block of 36 bytes.

From now on, we are splitting the packets according to the needed
boundary of pixel format (or arbitrarily for compressed). As a side effect,
the packets may be slightly bigger up to MTU size.
---
 configure.ac     |  5 +++++
 src/transmit.cpp | 11 +++++++----
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/configure.ac b/configure.ac
index 81f2149f4..eb5f230c6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -245,6 +245,11 @@ static inline int posix_memalign(void **memptr, size_t alignment, size_t size)
 }
 #endif // POSIX_MEMALIGN
 #endif // defined HAVE_MACOSX && OS_VERSION_MAJOR <= 9
+
+#undef MIN
+#define MIN(a,b) (((a)<(b))?(a):(b))
+#undef MAX
+#define MAX(a,b) (((a)>(b))?(a):(b))
 ])
 
 # @param $1 name of the module
diff --git a/src/transmit.cpp b/src/transmit.cpp
index b9a0da54f..f487c1b9e 100644
--- a/src/transmit.cpp
+++ b/src/transmit.cpp
@@ -445,7 +445,7 @@ static uint32_t format_interl_fps_hdr_row(enum interlacing_t interlacing, double
         return htonl(tmp);
 }
 static inline int get_data_len(bool with_fec, int mtu, int hdrs_len,
-                int fec_symbol_size, int *fec_symbol_offset)
+                int fec_symbol_size, int *fec_symbol_offset, int pf_block_size)
 {
         int data_len;
         data_len = mtu - hdrs_len;
@@ -461,7 +461,8 @@ static inline int get_data_len(bool with_fec, int mtu, int hdrs_len,
                         }
                 }
         } else {
-                data_len = (data_len / 48) * 48;
+                pf_block_size = MAX(pf_block_size, 1); // compressed formats have usually 0
+                data_len = (data_len / pf_block_size) * pf_block_size;
         }
         return data_len;
 }
@@ -590,7 +591,8 @@ tx_send_base(struct tx *tx, struct video_frame *frame, struct rtp *rtp_session,
         int packet_count = 0;
         do {
                 pos += get_data_len(frame->fec_params.type != FEC_NONE, tx->mtu, hdrs_len,
-                                fec_symbol_size, &fec_symbol_offset);
+                                fec_symbol_size, &fec_symbol_offset,
+                                get_pf_block_size(frame->color_spec));
                 packet_count += 1;
         } while (pos < (unsigned int) tile->data_len);
         if(tx->fec_scheme == FEC_MULT) {
@@ -641,7 +643,8 @@ tx_send_base(struct tx *tx, struct video_frame *frame, struct rtp *rtp_session,
 
                 data = tile->data + pos;
                 data_len = get_data_len(frame->fec_params.type != FEC_NONE, tx->mtu, hdrs_len,
-                                fec_symbol_size, &fec_symbol_offset);
+                                fec_symbol_size, &fec_symbol_offset,
+                                get_pf_block_size(frame->color_spec));
                 if (pos + data_len >= (unsigned int) tile->data_len) {
                         if (send_m) {
                                 m = 1;