From 974227a3fcfa5b60921aeb71d43da4ac84c73d91 Mon Sep 17 00:00:00 2001
From: Romain Vimont <rom@rom1v.com>
Date: Thu, 2 Mar 2023 09:37:36 +0100
Subject: [PATCH] Use frame source trait in decoder

---
 app/src/decoder.c | 56 +++++------------------------------------------
 app/src/decoder.h | 10 ++-------
 app/src/scrcpy.c  |  6 +++--
 3 files changed, 12 insertions(+), 60 deletions(-)

diff --git a/app/src/decoder.c b/app/src/decoder.c
index e4d59628..2931c1ec 100644
--- a/app/src/decoder.c
+++ b/app/src/decoder.c
@@ -11,32 +11,6 @@
 /** Downcast packet_sink to decoder */
 #define DOWNCAST(SINK) container_of(SINK, struct sc_decoder, packet_sink)
 
-static void
-sc_decoder_close_first_sinks(struct sc_decoder *decoder, unsigned count) {
-    while (count) {
-        struct sc_frame_sink *sink = decoder->sinks[--count];
-        sink->ops->close(sink);
-    }
-}
-
-static inline void
-sc_decoder_close_sinks(struct sc_decoder *decoder) {
-    sc_decoder_close_first_sinks(decoder, decoder->sink_count);
-}
-
-static bool
-sc_decoder_open_sinks(struct sc_decoder *decoder, const AVCodecContext *ctx) {
-    for (unsigned i = 0; i < decoder->sink_count; ++i) {
-        struct sc_frame_sink *sink = decoder->sinks[i];
-        if (!sink->ops->open(sink, ctx)) {
-            sc_decoder_close_first_sinks(decoder, i);
-            return false;
-        }
-    }
-
-    return true;
-}
-
 static bool
 sc_decoder_open(struct sc_decoder *decoder, const AVCodec *codec) {
     decoder->codec_ctx = avcodec_alloc_context3(codec);
@@ -66,7 +40,8 @@ sc_decoder_open(struct sc_decoder *decoder, const AVCodec *codec) {
         return false;
     }
 
-    if (!sc_decoder_open_sinks(decoder, decoder->codec_ctx)) {
+    if (!sc_frame_source_sinks_open(&decoder->frame_source,
+                                    decoder->codec_ctx)) {
         av_frame_free(&decoder->frame);
         avcodec_close(decoder->codec_ctx);
         avcodec_free_context(&decoder->codec_ctx);
@@ -78,24 +53,12 @@ sc_decoder_open(struct sc_decoder *decoder, const AVCodec *codec) {
 
 static void
 sc_decoder_close(struct sc_decoder *decoder) {
-    sc_decoder_close_sinks(decoder);
+    sc_frame_source_sinks_close(&decoder->frame_source);
     av_frame_free(&decoder->frame);
     avcodec_close(decoder->codec_ctx);
     avcodec_free_context(&decoder->codec_ctx);
 }
 
-static bool
-push_frame_to_sinks(struct sc_decoder *decoder, const AVFrame *frame) {
-    for (unsigned i = 0; i < decoder->sink_count; ++i) {
-        struct sc_frame_sink *sink = decoder->sinks[i];
-        if (!sink->ops->push(sink, frame)) {
-            return false;
-        }
-    }
-
-    return true;
-}
-
 static bool
 sc_decoder_push(struct sc_decoder *decoder, const AVPacket *packet) {
     bool is_config = packet->pts == AV_NOPTS_VALUE;
@@ -124,7 +87,8 @@ sc_decoder_push(struct sc_decoder *decoder, const AVPacket *packet) {
         }
 
         // a frame was received
-        bool ok = push_frame_to_sinks(decoder, decoder->frame);
+        bool ok = sc_frame_source_sinks_push(&decoder->frame_source,
+                                             decoder->frame);
         // A frame lost should not make the whole pipeline fail. The error, if
         // any, is already logged.
         (void) ok;
@@ -157,7 +121,7 @@ sc_decoder_packet_sink_push(struct sc_packet_sink *sink,
 void
 sc_decoder_init(struct sc_decoder *decoder, const char *name) {
     decoder->name = name; // statically allocated
-    decoder->sink_count = 0;
+    sc_frame_source_init(&decoder->frame_source);
 
     static const struct sc_packet_sink_ops ops = {
         .open = sc_decoder_packet_sink_open,
@@ -167,11 +131,3 @@ sc_decoder_init(struct sc_decoder *decoder, const char *name) {
 
     decoder->packet_sink.ops = &ops;
 }
-
-void
-sc_decoder_add_sink(struct sc_decoder *decoder, struct sc_frame_sink *sink) {
-    assert(decoder->sink_count < SC_DECODER_MAX_SINKS);
-    assert(sink);
-    assert(sink->ops);
-    decoder->sinks[decoder->sink_count++] = sink;
-}
diff --git a/app/src/decoder.h b/app/src/decoder.h
index aace1af6..87aaf6a2 100644
--- a/app/src/decoder.h
+++ b/app/src/decoder.h
@@ -3,22 +3,19 @@
 
 #include "common.h"
 
+#include "trait/frame_source.h"
 #include "trait/packet_sink.h"
 
 #include <stdbool.h>
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
 
-#define SC_DECODER_MAX_SINKS 2
-
 struct sc_decoder {
     struct sc_packet_sink packet_sink; // packet sink trait
+    struct sc_frame_source frame_source; // frame source trait
 
     const char *name; // must be statically allocated (e.g. a string literal)
 
-    struct sc_frame_sink *sinks[SC_DECODER_MAX_SINKS];
-    unsigned sink_count;
-
     AVCodecContext *codec_ctx;
     AVFrame *frame;
 };
@@ -27,7 +24,4 @@ struct sc_decoder {
 void
 sc_decoder_init(struct sc_decoder *decoder, const char *name);
 
-void
-sc_decoder_add_sink(struct sc_decoder *decoder, struct sc_frame_sink *sink);
-
 #endif
diff --git a/app/src/scrcpy.c b/app/src/scrcpy.c
index d9625a44..54858c01 100644
--- a/app/src/scrcpy.c
+++ b/app/src/scrcpy.c
@@ -665,7 +665,8 @@ aoa_hid_end:
         }
         screen_initialized = true;
 
-        sc_decoder_add_sink(&s->video_decoder, &s->screen.frame_sink);
+        sc_frame_source_add_sink(&s->video_decoder.frame_source,
+                                 &s->screen.frame_sink);
     }
 
 #ifdef HAVE_V4L2
@@ -675,7 +676,8 @@ aoa_hid_end:
             goto end;
         }
 
-        sc_decoder_add_sink(&s->video_decoder, &s->v4l2_sink.frame_sink);
+        sc_frame_source_add_sink(&s->video_decoder.frame_source,
+                                 &s->v4l2_sink.frame_sink);
 
         v4l2_sink_initialized = true;
     }