sgienc: Use a local RLE encoding function

SGI RLE encoding is slighlty different than the one provided by rle
module (especially at high bit depth). The pixel count function however
does not change, so it is simply made library-public.

1 files changed, 40 insertions, 5 deletions

diff --git a/libavcodec/sgienc.c b/libavcodec/sgienc.c
index a449f8c03b..236c72b250 100644
--- a/libavcodec/sgienc.c
+++ b/libavcodec/sgienc.c
@@ -39,6 +39,44 @@ static av_cold int encode_init(AVCodecContext *avctx)
     return 0;
 }
 
+static int sgi_rle_encode(PutByteContext *pbc, const uint8_t *src,
+                          int w, int bpp)
+{
+    int val, count, x, start = bytestream2_tell_p(pbc);
+    void (*bytestream2_put)(PutByteContext *, unsigned int);
+
+    bytestream2_put = bytestream2_put_byte;
+
+    for (x = 0; x < w; x += count) {
+        /* see if we can encode the next set of pixels with RLE */
+        count = ff_rle_count_pixels(src, w - x, bpp, 1);
+        if (count > 1) {
+            if (bytestream2_get_bytes_left_p(pbc) < bpp * 2)
+                return AVERROR_INVALIDDATA;
+
+            val = *src;
+            bytestream2_put(pbc, count);
+            bytestream2_put(pbc, val);
+        } else {
+            int i;
+            /* fall back on uncompressed */
+            count = ff_rle_count_pixels(src, w - x, bpp, 0);
+            if (bytestream2_get_bytes_left_p(pbc) < bpp * (count + 1))
+                return AVERROR_INVALIDDATA;
+
+            bytestream2_put(pbc, count + 0x80);
+            for (i = 0; i < count; i++) {
+                val = src[i];
+                bytestream2_put(pbc, val);
+            }
+        }
+
+        src += count * bpp;
+    }
+
+    return bytestream2_tell_p(pbc) - start;
+}
+
 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                         const AVFrame *frame, int *got_packet)
 {
@@ -110,7 +148,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
     length = SGI_HEADER_SIZE;
     if (avctx->coder_type == FF_CODER_TYPE_RAW)
         length += depth * height * width;
-    else // assume ff_rl_encode() produces at most 2x size of input
+    else // assume sgi_rle_encode() produces at most 2x size of input
         length += tablesize * 2 + depth * height * (2 * width + 1);
 
     if ((ret = ff_alloc_packet(pkt, bytes_per_channel * length)) < 0) {
@@ -166,15 +204,12 @@ FF_ENABLE_DEPRECATION_WARNINGS
                 for (x = 0; x < width; x++)
                     encode_buf[x] = in_buf[depth * x];
 
-                length = ff_rle_encode(pbc.buffer,
-                                       bytestream2_get_bytes_left_p(&pbc),
-                                       encode_buf, 1, width, 0, 0, 0x80, 0);
+                length = sgi_rle_encode(&pbc, encode_buf, width, 1);
                 if (length < 1) {
                     av_free(encode_buf);
                     return -1;
                 }
 
-                bytestream2_skip_p(&pbc, length);
                 bytestream2_put_be32(&tablen_pcb, length);
                 in_buf -= p->linesize[0];
             }