avcodec: Constify AVCodecs

[ffmpeg] / libavcodec / magicyuv.c

diff --git a/libavcodec/magicyuv.c b/libavcodec/magicyuv.c
index 17dea69d76fc4795023dca098c79891e2abf580f..594196063bd9eab3000360fa99897660b7f81689 100644 (file)
--- a/libavcodec/magicyuv.c
+++ b/libavcodec/magicyuv.c
@@ -25,7 +25,6 @@
 #define CACHED_BITSTREAM_READER !ARCH_X86_32
 
 #include "libavutil/pixdesc.h"
-#include "libavutil/qsort.h"
 
 #include "avcodec.h"
 #include "bytestream.h"
@@ -47,9 +46,8 @@ typedef enum Prediction {
 } Prediction;
 
 typedef struct HuffEntry {
-    uint16_t sym;
     uint8_t  len;
-    uint32_t code;
+    uint16_t sym;
 } HuffEntry;
 
 typedef struct MagicYUVContext {
@@ -74,29 +72,22 @@ typedef struct MagicYUVContext {
     LLVidDSPContext   llviddsp;
 } MagicYUVContext;
 
-static int huff_cmp_len(const void *a, const void *b)
+static int huff_build(const uint8_t len[], uint16_t codes_pos[33],
+                      VLC *vlc, int nb_elems, void *logctx)
 {
-    const HuffEntry *aa = a, *bb = b;
-    return (bb->len - aa->len) * 4096 + aa->sym - bb->sym;
-}
+    HuffEntry he[4096];
 
-static int huff_build(HuffEntry he[], VLC *vlc, int nb_elems)
-{
-    uint32_t code;
+    for (int i = 31; i > 0; i--)
+        codes_pos[i] += codes_pos[i + 1];
 
-    AV_QSORT(he, nb_elems, HuffEntry, huff_cmp_len);
-
-    code = 0;
-    for (unsigned i = 0; i < nb_elems; i++) {
-        he[i].code = code >> (32 - he[i].len);
-        code += 0x80000000u >> (he[i].len - 1);
-    }
+    for (unsigned i = nb_elems; i-- > 0;)
+        he[--codes_pos[len[i]]] = (HuffEntry){ len[i], i };
 
     ff_free_vlc(vlc);
-    return ff_init_vlc_sparse(vlc, FFMIN(he[0].len, 12), nb_elems,
-                              &he[0].len,  sizeof(he[0]), sizeof(he[0].len),
-                              &he[0].code, sizeof(he[0]), sizeof(he[0].code),
-                              &he[0].sym,  sizeof(he[0]), sizeof(he[0].sym),  0);
+    return ff_init_vlc_from_lengths(vlc, FFMIN(he[0].len, 12), nb_elems,
+                                    &he[0].len, sizeof(he[0]),
+                                    &he[0].sym, sizeof(he[0]), sizeof(he[0].sym),
+                                    0, 0, logctx);
 }
 
 static void magicyuv_median_pred16(uint16_t *dst, const uint16_t *src1,
@@ -388,7 +379,8 @@ static int build_huffman(AVCodecContext *avctx, const uint8_t *table,
 {
     MagicYUVContext *s = avctx->priv_data;
     GetByteContext gb;
-    HuffEntry he[4096];
+    uint8_t len[4096];
+    uint16_t length_count[33] = { 0 };
     int i = 0, j = 0, k;
 
     bytestream2_init(&gb, table, table_size);
@@ -409,14 +401,13 @@ static int build_huffman(AVCodecContext *avctx, const uint8_t *table,
             return AVERROR_INVALIDDATA;
         }
 
-        for (; j < k; j++) {
-            he[j].sym = j;
-            he[j].len = x;
-        }
+        length_count[x] += l;
+        for (; j < k; j++)
+            len[j] = x;
 
         if (j == max) {
             j = 0;
-            if (huff_build(he, &s->vlc[i], max)) {
+            if (huff_build(len, length_count, &s->vlc[i], max, avctx)) {
                 av_log(avctx, AV_LOG_ERROR, "Cannot build Huffman codes\n");
                 return AVERROR_INVALIDDATA;
             }
@@ -424,6 +415,7 @@ static int build_huffman(AVCodecContext *avctx, const uint8_t *table,
             if (i == s->planes) {
                 break;
             }
+            memset(length_count, 0, sizeof(length_count));
         }
     }
 
@@ -627,6 +619,9 @@ static int magy_decode_frame(AVCodecContext *avctx, void *data,
 
         s->slices[i][j].start = offset + header_size;
         s->slices[i][j].size  = avpkt->size - s->slices[i][j].start;
+
+        if (s->slices[i][j].size < 2)
+            return AVERROR_INVALIDDATA;
     }
 
     if (bytestream2_get_byteu(&gb) != s->planes)
@@ -699,7 +694,7 @@ static av_cold int magy_decode_end(AVCodecContext *avctx)
     return 0;
 }
 
-AVCodec ff_magicyuv_decoder = {
+const AVCodec ff_magicyuv_decoder = {
     .name             = "magicyuv",
     .long_name        = NULL_IF_CONFIG_SMALL("MagicYUV video"),
     .type             = AVMEDIA_TYPE_VIDEO,