Merge commit '1f3e56b6'

* commit '1f3e56b6':
  gifdec: convert to bytestream2

Conflicts:
	libavcodec/gifdec.c
	libavcodec/lzw.c
	libavcodec/lzw.h

See: 3fd60d80Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/gifdec.c

@@ -64,7 +64,6 @@ typedef struct GifState {
     int stored_bg_color;
 
     GetByteContext gb;
-    /* LZW compatible decoder */
     LZWState *lzw;
 
     /* aux buffers */
@@ -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)