Merge remote-tracking branch 'qatar/master'

[ffmpeg] / libavcodec / pngdec.c

diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 967d5567e891e6bbbac8d260b8ef62c065e95606..5bfe07ba5ded76787f9238cb93fc797058e1e445 100644 (file)
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -395,21 +395,23 @@ static int decode_frame(AVCodecContext *avctx,
     AVFrame *p;
     uint8_t *crow_buf_base = NULL;
     uint32_t tag, length;
+    int64_t sig;
     int ret;
 
     FFSWAP(AVFrame *, s->current_picture, s->last_picture);
     avctx->coded_frame= s->current_picture;
     p = s->current_picture;
 
+    bytestream2_init(&s->gb, buf, buf_size);
+
     /* check signature */
-    if (buf_size < 8 ||
-        memcmp(buf, ff_pngsig, 8) != 0 &&
-        memcmp(buf, ff_mngsig, 8) != 0) {
+    sig = bytestream2_get_be64(&s->gb);
+    if (sig != PNGSIG &&
+        sig != MNGSIG) {
         av_log(avctx, AV_LOG_ERROR, "Missing png signature\n");
         return -1;
     }
 
-    bytestream2_init(&s->gb, buf + 8, buf_size - 8);
     s->y=
     s->state=0;
 //    memset(s, 0, sizeof(PNGDecContext));
@@ -494,13 +496,14 @@ static int decode_frame(AVCodecContext *avctx,
                 } else if (s->bit_depth == 16 &&
                            s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
                     avctx->pix_fmt = PIX_FMT_RGBA64BE;
-                } else if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
+                } else if ((s->bits_per_pixel == 1 || s->bits_per_pixel == 2 || s->bits_per_pixel == 4 || s->bits_per_pixel == 8) &&
+                           s->color_type == PNG_COLOR_TYPE_PALETTE) {
                     avctx->pix_fmt = PIX_FMT_PAL8;
                 } else if (s->bit_depth == 1) {
                     avctx->pix_fmt = PIX_FMT_MONOBLACK;
                 } else if (s->bit_depth == 8 &&
                            s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
-                    avctx->pix_fmt = PIX_FMT_GRAY8A;
+                    avctx->pix_fmt = PIX_FMT_Y400A;
                 } else {
                     av_log(avctx, AV_LOG_ERROR, "unsupported bit depth %d "
                                                 "and color type %d\n",
@@ -675,7 +678,10 @@ static int decode_frame(AVCodecContext *avctx,
 
      /* handle p-frames only if a predecessor frame is available */
      if(s->last_picture->data[0] != NULL) {
-         if(!(avpkt->flags & AV_PKT_FLAG_KEY)) {
+         if(   !(avpkt->flags & AV_PKT_FLAG_KEY)
+            && s->last_picture->width == s->current_picture->width
+            && s->last_picture->height== s->current_picture->height
+         ) {
             int i, j;
             uint8_t *pd = s->current_picture->data[0];
             uint8_t *pd_last = s->last_picture->data[0];