[FFmpeg-devel] [PATCH] movenc: write clap tag

[Dave Rice]

Resolves https://trac.ffmpeg.org/ticket/6145 and writes a clap atom that is coincident with the frames width and height.


From 23d80d0d47829fed61e817b1e7c3f6d420c9ab5c Mon Sep 17 00:00:00 2001
From: Dave Rice <dave at dericed.com>
Date: Thu, 6 Jul 2017 21:12:38 -0400
Subject: [PATCH] movenc: write clap tag

---
 libavformat/movenc.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 88f2f2c819..31a5de8d5c 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -1669,6 +1669,21 @@ static int mov_write_sv3d_tag(AVFormatContext *s, AVIOContext *pb, AVSphericalMa
     return update_size(pb, sv3d_pos);
 }
 
+static int mov_write_clap_tag(AVIOContext *pb, MOVTrack *track)
+{
+    avio_wb32(pb, 40);
+    ffio_wfourcc(pb, "clap");
+    avio_wb32(pb, track->par->width); /* apertureWidth_N */
+    avio_wb32(pb, 1); /* apertureWidth_D (= 1) */
+    avio_wb32(pb, track->height); /* apertureHeight_N */
+    avio_wb32(pb, 1); /* apertureHeight_D (= 1) */
+    avio_wb32(pb, 0); /* horizOff_N (= 0) */
+    avio_wb32(pb, 1); /* horizOff_D (= 1) */
+    avio_wb32(pb, 0); /* vertOff_N (= 0) */
+    avio_wb32(pb, 1); /* vertOff_D (= 1) */
+    return 40;
+}
+
 static int mov_write_pasp_tag(AVIOContext *pb, MOVTrack *track)
 {
     AVRational sar;
@@ -1939,6 +1954,10 @@ static int mov_write_video_tag(AVIOContext *pb, MOVMuxContext *mov, MOVTrack *tr
             av_log(mov->fc, AV_LOG_WARNING, "Not writing 'colr' atom. Format is not MOV or MP4.\n");
     }
 
+    if (track->mode == MODE_MOV) {
+        mov_write_clap_tag(pb, track);
+    }
+
     if (track->mode == MODE_MP4 && mov->fc->strict_std_compliance <= FF_COMPLIANCE_UNOFFICIAL) {
         AVStereo3D* stereo_3d = (AVStereo3D*) av_stream_get_side_data(track->st, AV_PKT_DATA_STEREO3D, NULL);
         AVSphericalMapping* spherical_mapping = (AVSphericalMapping*)av_stream_get_side_data(track->st, AV_PKT_DATA_SPHERICAL, NULL);
-- 
2.13.0