diff --git a/libavcodec/gifdec.c b/libavcodec/gifdec.c
index a6b6be0470..c7b9ac8726 100644
--- a/libavcodec/gifdec.c
+++ b/libavcodec/gifdec.c
@@ -64,7 +64,6 @@ typedef struct GifState {
     int stored_bg_color;
 
     GetByteContext gb;
-    /* LZW compatible decoder */
     LZWState *lzw;
 
     /* aux buffers */
@@ -140,11 +139,11 @@ static int gif_read_image(GifState *s, AVFrame *frame)
     if (bytestream2_get_bytes_left(&s->gb) < 9)
         return AVERROR_INVALIDDATA;
 
-    left = bytestream2_get_le16u(&s->gb);
-    top = bytestream2_get_le16u(&s->gb);
-    width = bytestream2_get_le16u(&s->gb);
+    left   = bytestream2_get_le16u(&s->gb);
+    top    = bytestream2_get_le16u(&s->gb);
+    width  = bytestream2_get_le16u(&s->gb);
     height = bytestream2_get_le16u(&s->gb);
-    flags = bytestream2_get_byteu(&s->gb);
+    flags  = bytestream2_get_byteu(&s->gb);
     is_interleaved = flags & 0x40;
     has_local_palette = flags & 0x80;
     bits_per_pixel = (flags & 0x07) + 1;
@@ -302,7 +301,7 @@ static int gif_read_extension(GifState *s)
         return AVERROR_INVALIDDATA;
 
     ext_code = bytestream2_get_byteu(&s->gb);
-    ext_len = bytestream2_get_byteu(&s->gb);
+    ext_len  = bytestream2_get_byteu(&s->gb);
 
     av_dlog(s->avctx, "ext_code=0x%x len=%d\n", ext_code, ext_len);
 
@@ -316,7 +315,7 @@ static int gif_read_extension(GifState *s)
         if (bytestream2_get_bytes_left(&s->gb) < 5)
             return AVERROR_INVALIDDATA;
 
-        gce_flags = bytestream2_get_byteu(&s->gb);
+        gce_flags    = bytestream2_get_byteu(&s->gb);
         bytestream2_skipu(&s->gb, 2);    // delay during which the frame is shown
         gce_transparent_index = bytestream2_get_byteu(&s->gb);
         if (gce_flags & 0x01)
@@ -370,7 +369,7 @@ static int gif_read_header1(GifState *s)
 
     /* read screen header */
     s->transparent_color_index = -1;
-    s->screen_width = bytestream2_get_le16u(&s->gb);
+    s->screen_width  = bytestream2_get_le16u(&s->gb);
     s->screen_height = bytestream2_get_le16u(&s->gb);
 
     v = bytestream2_get_byteu(&s->gb);
@@ -404,7 +403,7 @@ static int gif_read_header1(GifState *s)
 
 static int gif_parse_next_image(GifState *s, AVFrame *frame)
 {
-    while (bytestream2_get_bytes_left(&s->gb)) {
+    while (bytestream2_get_bytes_left(&s->gb) > 0) {
         int code = bytestream2_get_byte(&s->gb);
         int ret;
 
@@ -502,7 +501,7 @@ static int gif_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, A
         return ret;
     *got_frame = 1;
 
-    return avpkt->size;
+    return bytestream2_tell(&s->gb);
 }
 
 static av_cold int gif_decode_close(AVCodecContext *avctx)