Add SDL/FFmpeg video output

src/video/ffmpeg.c

@@ -0,0 +1,160 @@
+/*
+ * This file is part of Moonlight Embedded.
+ *
+ * Based on Moonlight Pc implementation
+ *
+ * Moonlight is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Moonlight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Moonlight; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "ffmpeg.h"
+
+#include <stdlib.h>
+#include <libswscale/swscale.h>
+#include <pthread.h>
+#include <stdio.h>
+
+// General decoder and renderer state
+static AVPacket pkt;
+static AVCodec* decoder;
+static AVCodecContext* decoder_ctx;
+static AVFrame* dec_frame;
+static struct SwsContext* scaler_ctx;
+
+#define BYTES_PER_PIXEL 4
+
+// This function must be called before
+// any other decoding functions
+int ffmpeg_init(int width, int height, int perf_lvl, int thread_count) {
+  // Initialize the avcodec library and register codecs
+  av_log_set_level(AV_LOG_QUIET);
+  avcodec_register_all();
+
+  av_init_packet(&pkt);
+
+  decoder = avcodec_find_decoder(AV_CODEC_ID_H264);
+  if (decoder == NULL) {
+    printf("Couldn't find H264 decoder");
+    return -1;
+  }
+
+  decoder_ctx = avcodec_alloc_context3(decoder);
+  if (decoder_ctx == NULL) {
+    printf("Couldn't allocate context");
+    return -1;
+  }
+
+  if (perf_lvl & DISABLE_LOOP_FILTER)
+    // Skip the loop filter for performance reasons
+    decoder_ctx->skip_loop_filter = AVDISCARD_ALL;
+
+  if (perf_lvl & LOW_LATENCY_DECODE)
+    // Use low delay single threaded encoding
+    decoder_ctx->flags |= CODEC_FLAG_LOW_DELAY;
+
+  if (perf_lvl & SLICE_THREADING)
+    decoder_ctx->thread_type = FF_THREAD_SLICE;
+  else
+    decoder_ctx->thread_type = FF_THREAD_FRAME;
+
+  decoder_ctx->thread_count = thread_count;
+
+  decoder_ctx->width = width;
+  decoder_ctx->height = height;
+  decoder_ctx->pix_fmt = PIX_FMT_YUV420P;
+
+  int err = avcodec_open2(decoder_ctx, decoder, NULL);
+  if (err < 0) {
+    printf("Couldn't open codec");
+    return err;
+  }
+
+  dec_frame = av_frame_alloc();
+  if (dec_frame == NULL) {
+    printf("Couldn't allocate frame");
+    return -1;
+  }
+  
+  int filtering;
+  if (perf_lvl & FAST_BILINEAR_FILTERING)
+    filtering = SWS_FAST_BILINEAR;
+  else if (perf_lvl & BILINEAR_FILTERING)
+    filtering = SWS_BILINEAR;
+  else
+    filtering = SWS_BICUBIC;
+
+  scaler_ctx = sws_getContext(decoder_ctx->width, decoder_ctx->height, decoder_ctx->pix_fmt, decoder_ctx->width, decoder_ctx->height, PIX_FMT_YUV420P, filtering, NULL, NULL, NULL);
+  if (scaler_ctx == NULL) {
+    printf("Couldn't get scaler context");
+    return -1;
+  }
+
+  return 0;
+}
+
+// This function must be called after
+// decoding is finished
+void ffmpeg_destroy(void) {
+  if (decoder_ctx) {
+    avcodec_close(decoder_ctx);
+    av_free(decoder_ctx);
+    decoder_ctx = NULL;
+  }
+  if (scaler_ctx) {
+    sws_freeContext(scaler_ctx);
+    scaler_ctx = NULL;
+  }
+  if (dec_frame) {
+    av_frame_free(&dec_frame);
+    dec_frame = NULL;
+  }
+}
+
+int ffmpeg_draw_frame(AVPicture pict) {
+  int err = sws_scale(scaler_ctx, (const uint8_t* const*) dec_frame->data, dec_frame->linesize, 0, decoder_ctx->height, pict.data, pict.linesize);
+
+  if (err != decoder_ctx->height) {
+    printf("Scaling failed");
+    return 0;
+  }
+  
+  return 1;
+}
+
+// packets must be decoded in order
+// indata must be inlen + FF_INPUT_BUFFER_PADDING_SIZE in length
+int ffmpeg_decode(unsigned char* indata, int inlen) {
+  int err;
+  int got_pic = 0;
+
+  pkt.data = indata;
+  pkt.size = inlen;
+
+  while (pkt.size > 0) {
+    got_pic = 0;
+    err = avcodec_decode_video2(decoder_ctx, dec_frame, &got_pic, &pkt);
+    if (err < 0) {
+      printf("Decode failed");
+      got_pic = 0;
+      break;
+    }
+
+    pkt.size -= err;
+    pkt.data += err;
+  }
+  
+  if (got_pic)
+    return 1;
+
+  return err < 0 ? err : 0;
+}