[FFmpeg-devel] [RFC PATCH 3/5] yadif: Properly preserve CEA-708 closed captions

[Devin Heitmueller]

Various deinterlacing modes have the effect of doubling the
framerate, and we need to ensure that the caption data isn't
duplicated (or else you get double captions on-screen).

Use the new ccfifo mechanism for yadif (and yadif_cuda and bwdif
since they use the same yadif core) so that CEA-708 data is
properly preserved through this filter.

Signed-off-by: Devin Heitmueller <dheitmueller at ltnglobal.com>
---
 libavfilter/vf_bwdif.c      | 7 +++++++
 libavfilter/vf_yadif.c      | 6 ++++++
 libavfilter/vf_yadif_cuda.c | 8 ++++++++
 libavfilter/yadif.h         | 2 ++
 libavfilter/yadif_common.c  | 5 +++++
 5 files changed, 28 insertions(+)

diff --git a/libavfilter/vf_bwdif.c b/libavfilter/vf_bwdif.c
index 65c617ebb3..de937d83cf 100644
--- a/libavfilter/vf_bwdif.c
+++ b/libavfilter/vf_bwdif.c
@@ -297,6 +297,7 @@ static av_cold void uninit(AVFilterContext *ctx)
     av_frame_free(&yadif->prev);
     av_frame_free(&yadif->cur );
     av_frame_free(&yadif->next);
+    av_ccfifo_freep(&yadif->cc_fifo);
 }
 
 static const enum AVPixelFormat pix_fmts[] = {
@@ -332,6 +333,12 @@ static int config_props(AVFilterLink *link)
 
     if(yadif->mode&1)
         link->frame_rate = av_mul_q(link->src->inputs[0]->frame_rate, (AVRational){2,1});
+    else
+        link->frame_rate = ctx->inputs[0]->frame_rate;
+
+    if (!(yadif->cc_fifo = av_ccfifo_alloc(&link->frame_rate, ctx)))
+        av_log(ctx, AV_LOG_VERBOSE, "Failure to setup CC FIFO queue.  Captions will be passed through\n");
+
 
     if (link->w < 3 || link->h < 4) {
         av_log(ctx, AV_LOG_ERROR, "Video of less than 3 columns or 4 lines is not supported\n");
diff --git a/libavfilter/vf_yadif.c b/libavfilter/vf_yadif.c
index 1be02de1a9..b51d21f6ff 100644
--- a/libavfilter/vf_yadif.c
+++ b/libavfilter/vf_yadif.c
@@ -261,6 +261,7 @@ static av_cold void uninit(AVFilterContext *ctx)
     av_frame_free(&yadif->prev);
     av_frame_free(&yadif->cur );
     av_frame_free(&yadif->next);
+    av_ccfifo_freep(&yadif->cc_fifo);
 }
 
 static const enum AVPixelFormat pix_fmts[] = {
@@ -293,6 +294,11 @@ static int config_output(AVFilterLink *outlink)
     if(s->mode & 1)
         outlink->frame_rate = av_mul_q(ctx->inputs[0]->frame_rate,
                                     (AVRational){2, 1});
+    else
+        outlink->frame_rate = ctx->inputs[0]->frame_rate;
+
+    if (!(s->cc_fifo = av_ccfifo_alloc(&outlink->frame_rate, ctx)))
+        av_log(ctx, AV_LOG_VERBOSE, "Failure to setup CC FIFO queue.  Captions will be passed through\n");
 
     if (outlink->w < 3 || outlink->h < 3) {
         av_log(ctx, AV_LOG_ERROR, "Video of less than 3 columns or lines is not supported\n");
diff --git a/libavfilter/vf_yadif_cuda.c b/libavfilter/vf_yadif_cuda.c
index 685b8a2035..d96ec391a0 100644
--- a/libavfilter/vf_yadif_cuda.c
+++ b/libavfilter/vf_yadif_cuda.c
@@ -206,6 +206,9 @@ static av_cold void deint_cuda_uninit(AVFilterContext *ctx)
     av_frame_free(&y->cur);
     av_frame_free(&y->next);
 
+    if (yadif->cc_fifo)
+        av_cc_fifo_free(yadif->cc_fifo);
+
     av_buffer_unref(&s->device_ref);
     s->hwctx = NULL;
     av_buffer_unref(&s->input_frames_ref);
@@ -291,6 +294,11 @@ static int config_output(AVFilterLink *link)
     if(y->mode & 1)
         link->frame_rate = av_mul_q(ctx->inputs[0]->frame_rate,
                                     (AVRational){2, 1});
+    else
+        outlink->frame_rate = ctx->inputs[0]->frame_rate;
+
+    if (!(s->cc_fifo = av_cc_fifo_alloc(&outlink->frame_rate, ctx)))
+        av_log(ctx, AV_LOG_VERBOSE, "Failure to setup CC FIFO queue.  Captions will be passed through\n");
 
     if (link->w < 3 || link->h < 3) {
         av_log(ctx, AV_LOG_ERROR, "Video of less than 3 columns or lines is not supported\n");
diff --git a/libavfilter/yadif.h b/libavfilter/yadif.h
index c928911b35..ccd4304860 100644
--- a/libavfilter/yadif.h
+++ b/libavfilter/yadif.h
@@ -21,6 +21,7 @@
 
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
+#include "libavutil/ccfifo.h"
 #include "avfilter.h"
 
 enum YADIFMode {
@@ -76,6 +77,7 @@ typedef struct YADIFContext {
     int eof;
     uint8_t *temp_line;
     int temp_line_size;
+    AVCCFifo *cc_fifo;
 
     /*
      * An algorithm that treats first and/or last fields in a sequence
diff --git a/libavfilter/yadif_common.c b/libavfilter/yadif_common.c
index a10cf7a17f..f95b8c10d3 100644
--- a/libavfilter/yadif_common.c
+++ b/libavfilter/yadif_common.c
@@ -43,6 +43,7 @@ static int return_frame(AVFilterContext *ctx, int is_second)
             return AVERROR(ENOMEM);
 
         av_frame_copy_props(yadif->out, yadif->cur);
+        av_ccfifo_inject(yadif->cc_fifo, yadif->out);
         yadif->out->interlaced_frame = 0;
         if (yadif->current_field == YADIF_FIELD_BACK_END)
             yadif->current_field = YADIF_FIELD_END;
@@ -96,6 +97,8 @@ int ff_yadif_filter_frame(AVFilterLink *link, AVFrame *frame)
 
     av_assert0(frame);
 
+    av_ccfifo_extract(yadif->cc_fifo, frame);
+
     if (yadif->frame_pending)
         return_frame(ctx, 1);
 
@@ -137,6 +140,7 @@ int ff_yadif_filter_frame(AVFilterLink *link, AVFrame *frame)
         if (!yadif->out)
             return AVERROR(ENOMEM);
 
+        av_ccfifo_inject(yadif->cc_fifo, yadif->out);
         av_frame_free(&yadif->prev);
         if (yadif->out->pts != AV_NOPTS_VALUE)
             yadif->out->pts *= 2;
@@ -148,6 +152,7 @@ int ff_yadif_filter_frame(AVFilterLink *link, AVFrame *frame)
         return AVERROR(ENOMEM);
 
     av_frame_copy_props(yadif->out, yadif->cur);
+    av_ccfifo_inject(yadif->cc_fifo, yadif->out);
     yadif->out->interlaced_frame = 0;
 
     if (yadif->out->pts != AV_NOPTS_VALUE)
-- 
2.35.1.655.ga68dfadae5