Add encoder.cc for profile purposes.

src/wasms/encoder.cc

+#include <stdio.h>
+#include <stdint.h>
+#include <malloc.h>
+#include "wasm.h"
+
+extern "C" {
+#include <libavcodec/avcodec.h>
+#include <libavformat/avformat.h>
+#include <libswscale/swscale.h>
+#include <libavutil/avutil.h>
+}
+
+#include <chrono>
+#include <ctime>
+
+///////////////////////////////////////////////////////////////////////////////
+//                               Encoding Part                               //
+///////////////////////////////////////////////////////////////////////////////
+
+static int width_ = 0;
+static int height_ = 0;
+static int framerate_ = 0;
+static int timescale = 90000;
+static AVFrame *rgbaFrame;
+static unsigned frameIndex = 0;
+static AVFrame         *frame;
+static AVPacket        *packet;
+static AVCodecContext  *cc;
+static struct SwsContext* swsCtx = NULL;
+static AVPacket *lastPkt = NULL;
+
+
+EM_PORT_API(int) getPackets(uint8_t *buffer, uint32_t size, uint32_t *osize);
+
+EM_PORT_API(uint8_t)  encodeInit(int width, int height, int fps) {
+
+    int ret = 0;
+
+    width_ = width;
+    height_ = height;
+    framerate_ = fps;
+
+    const AVCodec *encoder = avcodec_find_encoder_by_name("libx264");
+    if (encoder == NULL) {
+        fprintf(stderr, "Unable to find H.264 decoder\n");
+        return 1;
+    }
+    cc = avcodec_alloc_context3(encoder);
+    if (cc == NULL) {
+        fprintf(stderr, "Unable to alloc codec context\n");
+        return 2;
+    }
+
+    // Setup encode parameters
+    cc->width = width;
+    cc->height = height;
+    cc->pix_fmt = AV_PIX_FMT_YUV420P;
+    cc->time_base = (AVRational){1, timescale};
+    cc->gop_size = 0;
+
+    if ((ret = avcodec_open2(cc, encoder, NULL) < 0)) {
+        fprintf(stderr, "Unable to open codec context: %s\n",
+            av_err2str(ret));
+        return 3;
+    }
+
+    packet = av_packet_alloc();
+    if (packet == NULL) {
+        fprintf(stderr, "Could not allocate packet\n");
+    }
+
+    frame = av_frame_alloc();
+    frame->format = cc->pix_fmt;
+    frame->width = cc->width;
+    frame->height = cc->height;
+
+    ret = av_frame_get_buffer(frame, 0);
+    if (ret < 0) {
+        fprintf(stderr, "Could not allocate the video frame data\n");
+        return 4;
+    }
+
+    swsCtx = sws_getCachedContext(swsCtx, width, height, AV_PIX_FMT_RGBA,
+        width, height, AV_PIX_FMT_YUV420P,
+        SWS_BICUBIC,
+        NULL, NULL, NULL);
+
+    return 0;
+}
+
+static std::chrono::duration<double> total;
+
+/* Ret Values:
+ * 0: Success
+ * 1: AGAIN
+ * 2: Buffer too small
+ * 3: ERROR */
+EM_PORT_API(int) encode(uint8_t *data, uint8_t *buffer, uint32_t size, uint32_t *osize) {
+    int ret = 0;
+
+    if (av_frame_make_writable(frame) < 0) {
+        fprintf(stderr, "Fail to make frame writable\n");
+    }
+
+    rgbaFrame = av_frame_alloc();
+    rgbaFrame->format =AV_PIX_FMT_RGBA;
+    rgbaFrame->height = cc->height;
+    rgbaFrame->width = cc->width;
+    avpicture_fill((AVPicture*)rgbaFrame, data, AV_PIX_FMT_RGBA, width_, height_);
+
+    //转换的YUV数据存放在frame
+    int outSliceH = sws_scale(swsCtx, (const uint8_t* const*)rgbaFrame->data, rgbaFrame->linesize, 0, height_,
+        frame->data, frame->linesize);
+
+    if (outSliceH <= 0) {
+        printf("outSliceH <= 0 \n");
+        return 3;
+    }
+
+
+    frame->pts = timescale / framerate_ * frameIndex;
+    frame->pict_type = AV_PICTURE_TYPE_I;
+    ++frameIndex;
+
+    auto start = std::chrono::system_clock::now();
+    // Encode
+    ret = avcodec_send_frame(cc, frame);
+    if (ret < 0) {
+        fprintf(stderr, "Fail to encoding\n");
+    }
+    auto end = std::chrono::system_clock::now();
+
+    std::chrono::duration<double> elapsed_seconds = end - start;
+    total += elapsed_seconds;
+    std::time_t end_time = std::chrono::system_clock::to_time_t(end);
+
+    printf("elapsed time (wasm): %lf\nTotal elapsed (wasm): %lf\n",
+           elapsed_seconds.count(),
+           total.count());
+
+    return getPackets(buffer, size, osize);
+}
+
+/* Ret Values:
+ * 0: Success
+ * 1: AGAIN or EOF
+ * 2: Buffer too small
+ * 3: ERROR  */
+EM_PORT_API(int) getPackets(uint8_t *buffer, uint32_t size, uint32_t *osize) {
+    int ret = 0;
+    uint8_t *pos = buffer;
+    int remainSize = size;
+
+    *osize = 0;
+
+    if (lastPkt != NULL && lastPkt->size > remainSize) {
+        memcpy(pos, lastPkt->data, lastPkt->size);
+        pos += lastPkt->size;
+        remainSize -= lastPkt->size;
+        av_packet_unref(lastPkt);
+        lastPkt = NULL;
+    } else if (lastPkt != NULL) {
+        /* Buffer is too small to containe the packet */
+        return 2;
+    }
+
+    while (1) {
+        ret = avcodec_receive_packet(cc, packet);
+
+        if (ret < 0) {
+            ret = 1;
+            goto DONE;
+        }
+
+        // For video frame avcodec_receive_packet should return
+        // only once.
+        if (remainSize > packet->size) {
+            memcpy(pos, packet->data, packet->size);
+            pos += packet->size;
+            remainSize -= packet->size;
+        } else {
+            lastPkt = packet;
+            break;
+        }
+
+        av_packet_unref(packet);
+
+    }
+
+  DONE:
+    *osize = size - remainSize;
+    return ret;
+}
+
+EM_PORT_API(int) flushEncoder() {
+    if (avcodec_send_frame(cc, NULL) < 0) {
+        return 1;
+    }
+
+    return 0;
+}
+
+int main(void) {}