[FFmpeg-devel] [PATCH v2] avcodec/libwebpenc_anim: support setting the duration of the last frame

[1035567130 at qq.com]

From: Wang Yaqiang <wangyaqiang03 at kuaishou.com>

Signed-off-by: Wang Yaqiang <wangyaqiang03 at kuaishou.com>
---
 libavcodec/libwebpenc_animencoder.c | 17 +++++++++++++++--
 libavcodec/libwebpenc_common.c      |  2 ++
 libavcodec/libwebpenc_common.h      |  1 +
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/libavcodec/libwebpenc_animencoder.c b/libavcodec/libwebpenc_animencoder.c
index c5361d7f92..558fcc246d 100644
--- a/libavcodec/libwebpenc_animencoder.c
+++ b/libavcodec/libwebpenc_animencoder.c
@@ -38,6 +38,7 @@ typedef struct LibWebPAnimContext {
     WebPAnimEncoder *enc;     // the main AnimEncoder object
     int64_t first_frame_pts;  // pts of the first encoded frame.
     int64_t end_pts;          // pts + duration of the last frame
+    int64_t prev_frame_pts;   // pts of the previously encoded frame.
 
     void           *first_frame_opaque;
     AVBufferRef    *first_frame_opaque_ref;
@@ -72,7 +73,19 @@ static int libwebp_anim_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
         if (s->done) {  // Second flush: return empty package to denote finish.
             *got_packet = 0;
             return 0;
-        } else {  // First flush: assemble bitstream and return it.
+        } else {
+            if (s->cc.last_delay > 0) {
+                int timestamp_ms = avctx->time_base.num * (s->cc.last_delay + s->prev_frame_pts) * 1000 / avctx->time_base.den;
+                ret = WebPAnimEncoderAdd(s->enc, NULL, timestamp_ms, &s->cc.config);
+                if (!ret) {
+                    av_log(avctx, AV_LOG_ERROR,
+                           "Encoding WebP frame failed!\n");
+                    ret = AVERROR_EXTERNAL;
+                    goto end;
+                }
+                s->end_pts = s->prev_frame_pts + s->cc.last_delay;
+            }
+            // First flush: assemble bitstream and return it.
             WebPData assembled_data = { 0 };
             ret = WebPAnimEncoderAssemble(s->enc, &assembled_data);
             if (ret) {
@@ -137,7 +150,7 @@ static int libwebp_anim_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
 
         if (frame->pts != AV_NOPTS_VALUE)
             s->end_pts = frame->pts + frame->duration;
-
+        s->prev_frame_pts = frame->pts;
         ret = 0;
         *got_packet = 0;
 
diff --git a/libavcodec/libwebpenc_common.c b/libavcodec/libwebpenc_common.c
index 80040ea9e3..13fb6aa690 100644
--- a/libavcodec/libwebpenc_common.c
+++ b/libavcodec/libwebpenc_common.c
@@ -49,6 +49,8 @@ static const AVOption options[] = {
     { "cr_threshold","Conditional replenishment threshold",     OFFSET(cr_threshold), AV_OPT_TYPE_INT, { .i64 =  0  },  0, INT_MAX, VE           },
     { "cr_size"     ,"Conditional replenishment block size",    OFFSET(cr_size)     , AV_OPT_TYPE_INT, { .i64 =  16 },  0, 256,     VE           },
     { "quality"     ,"Quality",                OFFSET(quality),  AV_OPT_TYPE_FLOAT, { .dbl =  75 }, 0, 100,                         VE           },
+    { "final_delay", "Force delay (in centiseconds) after the last frame", OFFSET(last_delay),
+      AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, VE },
     { NULL },
 };
 
diff --git a/libavcodec/libwebpenc_common.h b/libavcodec/libwebpenc_common.h
index 2735ccc88d..8e5f37805a 100644
--- a/libavcodec/libwebpenc_common.h
+++ b/libavcodec/libwebpenc_common.h
@@ -47,6 +47,7 @@ typedef struct LibWebPContextCommon {
     AVFrame *ref;
     int cr_size;
     int cr_threshold;
+    int last_delay;
 } LibWebPContextCommon;
 
 int ff_libwebp_error_to_averror(int err);
-- 
2.39.3 (Apple Git-146)