diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index 0ca07873b2..fbabbe6ea2 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -901,9 +901,9 @@ static void update_video_stats(OutputStream *ost, const AVPacket *pkt, int write
         ti1 = 0.01;
 
     bitrate     = (pkt->size * 8) / av_q2d(enc->time_base) / 1000.0;
-    avg_bitrate = (double)(ost->data_size * 8) / ti1 / 1000.0;
+    avg_bitrate = (double)(ost->data_size_enc * 8) / ti1 / 1000.0;
     fprintf(vstats_file, "s_size= %8.0fkB time= %0.3f br= %7.1fkbits/s avg_br= %7.1fkbits/s ",
-           (double)ost->data_size / 1024, ti1, bitrate, avg_bitrate);
+           (double)ost->data_size_enc / 1024, ti1, bitrate, avg_bitrate);
     fprintf(vstats_file, "type= %c\n", av_get_picture_type_char(ost->pict_type));
 }
 
@@ -979,6 +979,8 @@ static int encode_frame(OutputFile *of, OutputStream *ost, AVFrame *frame)
                    av_ts2str(pkt->duration), av_ts2timestr(pkt->duration, &enc->time_base));
         }
 
+        ost->data_size_enc += pkt->size;
+
         if (enc->codec_type == AVMEDIA_TYPE_VIDEO)
             update_video_stats(ost, pkt, !!vstats_filename);
 
@@ -1454,14 +1456,16 @@ static void print_final_stats(int64_t total_size)
     for (i = 0; i < nb_output_streams; i++) {
         OutputStream *ost = output_streams[i];
         AVCodecParameters *par = ost->st->codecpar;
+        const uint64_t s = ost->data_size_mux;
+
         switch (par->codec_type) {
-            case AVMEDIA_TYPE_VIDEO: video_size += ost->data_size; break;
-            case AVMEDIA_TYPE_AUDIO: audio_size += ost->data_size; break;
-            case AVMEDIA_TYPE_SUBTITLE: subtitle_size += ost->data_size; break;
-            default:                 other_size += ost->data_size; break;
+            case AVMEDIA_TYPE_VIDEO:    video_size    += s; break;
+            case AVMEDIA_TYPE_AUDIO:    audio_size    += s; break;
+            case AVMEDIA_TYPE_SUBTITLE: subtitle_size += s; break;
+            default:                    other_size    += s; break;
         }
         extra_size += par->extradata_size;
-        data_size  += ost->data_size;
+        data_size  += s;
         if (ost->enc_ctx &&
             (ost->enc_ctx->flags & (AV_CODEC_FLAG_PASS1 | AV_CODEC_FLAG_PASS2))
             != AV_CODEC_FLAG_PASS1)
@@ -1529,7 +1533,7 @@ static void print_final_stats(int64_t total_size)
             OutputStream *ost = output_streams[of->ost_index + j];
             enum AVMediaType type = ost->st->codecpar->codec_type;
 
-            total_size    += ost->data_size;
+            total_size    += ost->data_size_mux;
             total_packets += atomic_load(&ost->packets_written);
 
             av_log(NULL, AV_LOG_VERBOSE, "  Output stream #%d:%d (%s): ",
@@ -1543,7 +1547,7 @@ static void print_final_stats(int64_t total_size)
             }
 
             av_log(NULL, AV_LOG_VERBOSE, "%"PRIu64" packets muxed (%"PRIu64" bytes); ",
-                   atomic_load(&ost->packets_written), ost->data_size);
+                   atomic_load(&ost->packets_written), ost->data_size_mux);
 
             av_log(NULL, AV_LOG_VERBOSE, "\n");
         }
diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
index 74bc9220fc..ede0b2bd96 100644
--- a/fftools/ffmpeg.h
+++ b/fftools/ffmpeg.h
@@ -585,8 +585,10 @@ typedef struct OutputStream {
     int keep_pix_fmt;
 
     /* stats */
-    // combined size of all the packets written
-    uint64_t data_size;
+    // combined size of all the packets sent to the muxer
+    uint64_t data_size_mux;
+    // combined size of all the packets received from the encoder
+    uint64_t data_size_enc;
     // number of packets send to the muxer
     atomic_uint_least64_t packets_written;
     // number of frames/samples sent to the encoder
diff --git a/fftools/ffmpeg_mux.c b/fftools/ffmpeg_mux.c
index b424ef0021..b781e1f5a6 100644
--- a/fftools/ffmpeg_mux.c
+++ b/fftools/ffmpeg_mux.c
@@ -156,7 +156,7 @@ static int write_packet(OutputFile *of, OutputStream *ost, AVPacket *pkt)
     }
     ms->last_mux_dts = pkt->dts;
 
-    ost->data_size += pkt->size;
+    ost->data_size_mux += pkt->size;
     atomic_fetch_add(&ost->packets_written, 1);
 
     pkt->stream_index = ost->index;