From 6f5ad21f5757482b71a5d197f920ea39fb2f1167 Mon Sep 17 00:00:00 2001
From: Romain Vimont <rom@rom1v.com>
Date: Sun, 11 Apr 2021 15:01:05 +0200
Subject: [PATCH] Make decoder push frames to sinks

Now that screen implements the packet sink trait, make decoder push
packets to the sinks without depending on the concrete sink types.
---
 app/src/decoder.c | 68 ++++++++++++++++++++++++++++++++++++++++++-----
 app/src/decoder.h | 12 ++++-----
 app/src/scrcpy.c  |  4 ++-
 3 files changed, 70 insertions(+), 14 deletions(-)

diff --git a/app/src/decoder.c b/app/src/decoder.c
index 134ffd3c..34f2a15f 100644
--- a/app/src/decoder.c
+++ b/app/src/decoder.c
@@ -4,12 +4,40 @@
 
 #include "events.h"
 #include "video_buffer.h"
+#include "trait/frame_sink.h"
 #include "util/log.h"
 
 /** Downcast packet_sink to decoder */
 #define DOWNCAST(SINK) container_of(SINK, struct decoder, packet_sink)
 
-bool
+static void
+decoder_close_first_sinks(struct decoder *decoder, unsigned count) {
+    while (count) {
+        struct sc_frame_sink *sink = decoder->sinks[--count];
+        sink->ops->close(sink);
+    }
+}
+
+static inline void
+decoder_close_sinks(struct decoder *decoder) {
+    decoder_close_first_sinks(decoder, decoder->sink_count);
+}
+
+static bool
+decoder_open_sinks(struct decoder *decoder) {
+    for (unsigned i = 0; i < decoder->sink_count; ++i) {
+        struct sc_frame_sink *sink = decoder->sinks[i];
+        if (!sink->ops->open(sink)) {
+            LOGE("Could not open frame sink %d", i);
+            decoder_close_first_sinks(decoder, i);
+            return false;
+        }
+    }
+
+    return true;
+}
+
+static bool
 decoder_open(struct decoder *decoder, const AVCodec *codec) {
     decoder->codec_ctx = avcodec_alloc_context3(codec);
     if (!decoder->codec_ctx) {
@@ -31,16 +59,38 @@ decoder_open(struct decoder *decoder, const AVCodec *codec) {
         return false;
     }
 
+    if (!decoder_open_sinks(decoder)) {
+        LOGE("Could not open decoder sinks");
+        av_frame_free(&decoder->frame);
+        avcodec_close(decoder->codec_ctx);
+        avcodec_free_context(&decoder->codec_ctx);
+        return false;
+    }
+
     return true;
 }
 
-void
+static void
 decoder_close(struct decoder *decoder) {
+    decoder_close_sinks(decoder);
     av_frame_free(&decoder->frame);
     avcodec_close(decoder->codec_ctx);
     avcodec_free_context(&decoder->codec_ctx);
 }
 
+static bool
+push_frame_to_sinks(struct 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)) {
+            LOGE("Could not send frame to sink %d", i);
+            return false;
+        }
+    }
+
+    return true;
+}
+
 static bool
 decoder_push(struct decoder *decoder, const AVPacket *packet) {
     bool is_config = packet->pts == AV_NOPTS_VALUE;
@@ -57,7 +107,7 @@ decoder_push(struct decoder *decoder, const AVPacket *packet) {
     ret = avcodec_receive_frame(decoder->codec_ctx, decoder->frame);
     if (!ret) {
         // a frame was received
-        bool ok = video_buffer_push(decoder->video_buffer, decoder->frame);
+        bool ok = push_frame_to_sinks(decoder, decoder->frame);
         // A frame lost should not make the whole pipeline fail. The error, if
         // any, is already logged.
         (void) ok;
@@ -87,9 +137,7 @@ decoder_packet_sink_push(struct sc_packet_sink *sink, const AVPacket *packet) {
 }
 
 void
-decoder_init(struct decoder *decoder, struct video_buffer *vb) {
-    decoder->video_buffer = vb;
-
+decoder_init(struct decoder *decoder) {
     static const struct sc_packet_sink_ops ops = {
         .open = decoder_packet_sink_open,
         .close = decoder_packet_sink_close,
@@ -98,3 +146,11 @@ decoder_init(struct decoder *decoder, struct video_buffer *vb) {
 
     decoder->packet_sink.ops = &ops;
 }
+
+void
+decoder_add_sink(struct decoder *decoder, struct sc_frame_sink *sink) {
+    assert(decoder->sink_count < 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 e3730db5..bae97869 100644
--- a/app/src/decoder.h
+++ b/app/src/decoder.h
@@ -8,24 +8,22 @@
 #include <stdbool.h>
 #include <libavformat/avformat.h>
 
-struct video_buffer;
+#define DECODER_MAX_SINKS 1
 
 struct decoder {
     struct sc_packet_sink packet_sink; // packet sink trait
 
-    struct video_buffer *video_buffer;
+    struct sc_frame_sink *sinks[DECODER_MAX_SINKS];
+    unsigned sink_count;
 
     AVCodecContext *codec_ctx;
     AVFrame *frame;
 };
 
 void
-decoder_init(struct decoder *decoder, struct video_buffer *vb);
-
-bool
-decoder_open(struct decoder *decoder, const AVCodec *codec);
+decoder_init(struct decoder *decoder);
 
 void
-decoder_close(struct decoder *decoder);
+decoder_add_sink(struct decoder *decoder, struct sc_frame_sink *sink);
 
 #endif
diff --git a/app/src/scrcpy.c b/app/src/scrcpy.c
index ad705c4a..e8715cbe 100644
--- a/app/src/scrcpy.c
+++ b/app/src/scrcpy.c
@@ -318,7 +318,7 @@ scrcpy(const struct scrcpy_options *options) {
             file_handler_initialized = true;
         }
 
-        decoder_init(&decoder, &video_buffer);
+        decoder_init(&decoder);
         dec = &decoder;
     }
 
@@ -382,6 +382,8 @@ scrcpy(const struct scrcpy_options *options) {
         }
         screen_initialized = true;
 
+        decoder_add_sink(&decoder, &screen.frame_sink);
+
         if (options->turn_screen_off) {
             struct control_msg msg;
             msg.type = CONTROL_MSG_TYPE_SET_SCREEN_POWER_MODE;