pcx: return meaningful error codes.

libavcodec/pcx.c

@@ -94,7 +94,7 @@ static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
 
     if (buf[0] != 0x0a || buf[1] > 5) {
         av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
-        return -1;
+        return AVERROR_INVALIDDATA;
     }
 
     compressed = buf[2];
@@ -105,7 +105,7 @@ static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
 
     if (xmax < xmin || ymax < ymin) {
         av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
-        return -1;
+        return AVERROR_INVALIDDATA;
     }
 
     w = xmax - xmin + 1;
@@ -118,7 +118,7 @@ static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
 
     if (bytes_per_scanline < w * bits_per_pixel * nplanes / 8) {
         av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
-        return -1;
+        return AVERROR_INVALIDDATA;
     }
 
     switch ((nplanes<<8) + bits_per_pixel) {
@@ -136,7 +136,7 @@ static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
             break;
         default:
             av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
-            return -1;
+            return AVERROR_INVALIDDATA;
     }
 
     buf += 128;
@@ -144,13 +144,13 @@ static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
     if (p->data[0])
         avctx->release_buffer(avctx, p);
 
-    if (av_image_check_size(w, h, 0, avctx))
-        return -1;
+    if ((ret = av_image_check_size(w, h, 0, avctx)) < 0)
+        return ret;
     if (w != avctx->width || h != avctx->height)
         avcodec_set_dimensions(avctx, w, h);
-    if (ff_get_buffer(avctx, p) < 0) {
+    if ((ret = ff_get_buffer(avctx, p)) < 0) {
         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
-        return -1;
+        return ret;
     }
 
     p->pict_type = AV_PICTURE_TYPE_I;