From 8231080fd3db9a8bee73ae505d216e56d19c50fe Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Date: Tue, 15 Mar 2022 12:52:37 +0100
Subject: [PATCH] avcodec/lcldec: Use ff_inflate_init/end(), cleanup
 generically

Returns better error messages in case of error and deduplicates
the inflateInit() code and also allows to cleanup generically
in case of errors as it is save to call ff_inflate_end() if
ff_inflate_init() has not been called successfully.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
 configure           |  2 +-
 libavcodec/lcldec.c | 43 +++++++++++++++++--------------------------
 2 files changed, 18 insertions(+), 27 deletions(-)

diff --git a/configure b/configure
index 0061c54473..5e1f1c671c 100755
--- a/configure
+++ b/configure
@@ -2990,7 +2990,7 @@ xma1_decoder_select="wmapro_decoder"
 xma2_decoder_select="wmapro_decoder"
 ylc_decoder_select="bswapdsp"
 zerocodec_decoder_select="inflate_wrapper"
-zlib_decoder_deps="zlib"
+zlib_decoder_select="inflate_wrapper"
 zlib_encoder_deps="zlib"
 zmbv_decoder_select="inflate_wrapper"
 zmbv_encoder_deps="zlib"
diff --git a/libavcodec/lcldec.c b/libavcodec/lcldec.c
index b2ef85e5f9..4639313ebe 100644
--- a/libavcodec/lcldec.c
+++ b/libavcodec/lcldec.c
@@ -51,6 +51,7 @@
 #include "thread.h"
 
 #if CONFIG_ZLIB_DECODER
+#include "zlib_wrapper.h"
 #include <zlib.h>
 #endif
 
@@ -66,7 +67,7 @@ typedef struct LclDecContext {
     // Decompression buffer
     unsigned char* decomp_buf;
 #if CONFIG_ZLIB_DECODER
-    z_stream zstream;
+    FFZStream zstream;
 #endif
 } LclDecContext;
 
@@ -133,26 +134,27 @@ static unsigned int mszh_decomp(const unsigned char * srcptr, int srclen, unsign
 static int zlib_decomp(AVCodecContext *avctx, const uint8_t *src, int src_len, int offset, int expected)
 {
     LclDecContext *c = avctx->priv_data;
-    int zret = inflateReset(&c->zstream);
+    z_stream *const zstream = &c->zstream.zstream;
+    int zret = inflateReset(zstream);
     if (zret != Z_OK) {
         av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
         return AVERROR_UNKNOWN;
     }
-    c->zstream.next_in = src;
-    c->zstream.avail_in = src_len;
-    c->zstream.next_out = c->decomp_buf + offset;
-    c->zstream.avail_out = c->decomp_size - offset;
-    zret = inflate(&c->zstream, Z_FINISH);
+    zstream->next_in   = src;
+    zstream->avail_in  = src_len;
+    zstream->next_out  = c->decomp_buf + offset;
+    zstream->avail_out = c->decomp_size - offset;
+    zret = inflate(zstream, Z_FINISH);
     if (zret != Z_OK && zret != Z_STREAM_END) {
         av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
         return AVERROR_UNKNOWN;
     }
-    if (expected != (unsigned int)c->zstream.total_out) {
+    if (expected != (unsigned int)zstream->total_out) {
         av_log(avctx, AV_LOG_ERROR, "Decoded size differs (%d != %lu)\n",
-               expected, c->zstream.total_out);
+               expected, zstream->total_out);
         return AVERROR_UNKNOWN;
     }
-    return c->zstream.total_out;
+    return zstream->total_out;
 }
 #endif
 
@@ -608,18 +610,8 @@ static av_cold int decode_init(AVCodecContext *avctx)
 
     /* If needed init zlib */
 #if CONFIG_ZLIB_DECODER
-    if (avctx->codec_id == AV_CODEC_ID_ZLIB) {
-        int zret;
-        c->zstream.zalloc = Z_NULL;
-        c->zstream.zfree = Z_NULL;
-        c->zstream.opaque = Z_NULL;
-        zret = inflateInit(&c->zstream);
-        if (zret != Z_OK) {
-            av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
-            av_freep(&c->decomp_buf);
-            return AVERROR_UNKNOWN;
-        }
-    }
+    if (avctx->codec_id == AV_CODEC_ID_ZLIB)
+        return ff_inflate_init(&c->zstream, avctx);
 #endif
 
     return 0;
@@ -631,8 +623,7 @@ static av_cold int decode_end(AVCodecContext *avctx)
 
     av_freep(&c->decomp_buf);
 #if CONFIG_ZLIB_DECODER
-    if (avctx->codec_id == AV_CODEC_ID_ZLIB)
-        inflateEnd(&c->zstream);
+    ff_inflate_end(&c->zstream);
 #endif
 
     return 0;
@@ -649,7 +640,7 @@ const AVCodec ff_mszh_decoder = {
     .close          = decode_end,
     .decode         = decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
-    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
 };
 #endif
 
@@ -664,6 +655,6 @@ const AVCodec ff_zlib_decoder = {
     .close          = decode_end,
     .decode         = decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
-    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
 };
 #endif