Adding support for writing spherical metadata in MP4 files.
From 8eb03f706e5c490be7a9644018dd3efaf0154a81 Mon Sep 17 00:00:00 2001
From: Aaron Colwell <acolw...@google.com>
Date: Fri, 27 Jan 2017 10:07:44 -0800
Subject: [PATCH] movenc: Add support for writing st3d and sv3d boxes.
Adding support for writing spherical metadata in MP4 files.
---
libavformat/movenc.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 95 insertions(+)
diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index dc19838ed6..aa9ee2cccd 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -1603,6 +1603,92 @@ static int mov_write_subtitle_tag(AVIOContext *pb, MOVTrack *track)
return update_size(pb, pos);
}
+static int mov_write_st3d_tag(AVIOContext *pb, AVStereo3D *stereo_3d)
+{
+ int8_t stereo_mode;
+
+ if (stereo_3d->flags != 0) {
+ av_log(pb, AV_LOG_WARNING, "Unsupported stereo_3d flags %x. st3d not written.\n", stereo_3d->flags);
+ return 0;
+ }
+
+ switch (stereo_3d->type) {
+ case AV_STEREO3D_2D:
+ stereo_mode = 0;
+ break;
+ case AV_STEREO3D_TOPBOTTOM:
+ stereo_mode = 1;
+ break;
+ case AV_STEREO3D_SIDEBYSIDE:
+ stereo_mode = 2;
+ break;
+ default:
+ av_log(pb, AV_LOG_WARNING, "Unsupported stereo_3d type %d. st3d not written.\n", stereo_3d->type);
+ return 0;
+ }
+ avio_wb32(pb, 13); /* size */
+ ffio_wfourcc(pb, "st3d");
+ avio_wb32(pb, 0); /* version = 0 & flags = 0 */
+ avio_w8(pb, stereo_mode);
+ return 13;
+}
+
+static int mov_write_sv3d_tag(AVIOContext *pb, AVSphericalMapping *spherical_mapping)
+{
+ int64_t sv3d_pos = avio_tell(pb);
+ int64_t svhd_pos, proj_pos;
+
+ if (spherical_mapping->projection != AV_SPHERICAL_EQUIRECTANGULAR &&
+ spherical_mapping->projection != AV_SPHERICAL_CUBEMAP) {
+ av_log(pb, AV_LOG_WARNING, "Unsupported projection %d. sv3d not written.\n",
+ spherical_mapping->projection);
+ return 0;
+ }
+
+ avio_wb32(pb, 0); /* size */
+ ffio_wfourcc(pb, "sv3d");
+
+ svhd_pos = avio_tell(pb);
+ avio_wb32(pb, 0); /* size */
+ ffio_wfourcc(pb, "svhd");
+ avio_wb32(pb, 0); /* version = 0 & flags = 0 */
+ avio_put_str(pb, LIBAVFORMAT_IDENT); /* metadata_source */
+ update_size(pb, svhd_pos);
+
+ proj_pos = avio_tell(pb);
+ avio_wb32(pb, 0); /* size */
+ ffio_wfourcc(pb, "proj");
+
+ avio_wb32(pb, 24); /* size */
+ ffio_wfourcc(pb, "prhd");
+ avio_wb32(pb, 0); /* version = 0 & flags = 0 */
+ avio_wb32(pb, spherical_mapping->yaw);
+ avio_wb32(pb, spherical_mapping->pitch);
+ avio_wb32(pb, spherical_mapping->roll);
+
+ switch (spherical_mapping->projection) {
+ case AV_SPHERICAL_EQUIRECTANGULAR:
+ avio_wb32(pb, 28); /* size */
+ ffio_wfourcc(pb, "equi");
+ avio_wb32(pb, 0); /* version = 0 & flags = 0 */
+ avio_wb32(pb, 0); /* projection_bounds_top */
+ avio_wb32(pb, 0); /* projection_bounds_bottom */
+ avio_wb32(pb, 0); /* projection_bounds_left */
+ avio_wb32(pb, 0); /* projection_bounds_right */
+ break;
+ case AV_SPHERICAL_CUBEMAP:
+ avio_wb32(pb, 20); /* size */
+ ffio_wfourcc(pb, "cbmp");
+ avio_wb32(pb, 0); /* version = 0 & flags = 0 */
+ avio_wb32(pb, 0); /* layout */
+ avio_wb32(pb, 0); /* padding */
+ break;
+ }
+ update_size(pb, proj_pos);
+
+ return update_size(pb, sv3d_pos);
+}
+
static int mov_write_pasp_tag(AVIOContext *pb, MOVTrack *track)
{
AVRational sar;
@@ -1748,6 +1834,7 @@ static int mov_write_video_tag(AVIOContext *pb, MOVMuxContext *mov, MOVTrack *tr
int64_t pos = avio_tell(pb);
char compressor_name[32] = { 0 };
int avid = 0;
+ AVSphericalMapping* spherical_mapping;
avio_wb32(pb, 0); /* size */
if (mov->encryption_scheme != MOV_ENC_NONE) {
@@ -1873,6 +1960,14 @@ 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");
}
+ spherical_mapping = (AVSphericalMapping*)av_stream_get_side_data(track->st, AV_PKT_DATA_SPHERICAL, NULL);
+ if (spherical_mapping) {
+ AVStereo3D* stereo_3d = (AVStereo3D*) av_stream_get_side_data(track->st, AV_PKT_DATA_STEREO3D, NULL);
+ if (stereo_3d)
+ mov_write_st3d_tag(pb, stereo_3d);
+ mov_write_sv3d_tag(pb, spherical_mapping);
+ }
+
if (track->par->sample_aspect_ratio.den && track->par->sample_aspect_ratio.num) {
mov_write_pasp_tag(pb, track);
}
--
2.11.0.483.g087da7b7c-goog
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