04_a52dec.dpatch

现在关于h.264的源码很多

#! /bin/sh /usr/share/dpatch/dpatch-run
## 01_configure.dpatch by Christian Marillat <[e-mail]>
##
## All lines beginning with ## DP:' are a description of the patch.
## DP: Fix configure.

@DPATCH@

--- ffmpegcvs-20050716.orig/libavcodec/a52dec.c	2005-06-11 20:06:19.000000000 +0200
+++ ffmpegcvs-20050716/libavcodec/a52dec.c	2005-06-11 20:06:40.000000000 +0200
@@ -27,9 +27,45 @@
 
 #ifdef CONFIG_A52BIN
 #include <dlfcn.h>
-static const char* liba52name = "liba52.so.0";
+static const char* liba52name = "liba52.so";
+
+static int liba52_loaded = 0;
+static int liba52_load_error = 0;
+
+/*
+ * virtual method table
+ *
+ * using this function table so the liba52 doesn't
+ * have to be really linked together with ffmpeg
+ * and might be linked in runtime - this allows binary
+ * distribution of ffmpeg library which doens't depend
+ * on liba52 library - but if user has it installed
+ * it will be used - user might install such library
+ * separately
+ */
+static void* liba52_handle;
+
+static a52_state_t* (*a52_ptr_init)(uint32_t mm_accel);
+#define a52_init (*a52_ptr_init)
+static sample_t* (*a52_ptr_samples)(a52_state_t * state);
+#define a52_samples (*a52_ptr_samples)
+static int (*a52_ptr_syncinfo)(const uint8_t * buf, int * flags,
+                      int * sample_rate, int * bit_rate);
+#define a52_syncinfo (*a52_ptr_syncinfo)
+static int (*a52_ptr_frame)(a52_state_t * state, uint8_t * buf, int * flags,
+                   sample_t * level, sample_t bias);
+#define a52_frame (*a52_ptr_frame)
+//static void (*a52_ptr_dynrng)(a52_state_t * state,
+//                     sample_t (* call) (sample_t, void *), void * data);
+//#define a52_dynrng a52_ptr_dynrng
+static int (*a52_ptr_block)(a52_state_t * state);
+#define a52_block (*a52_ptr_block)
+static void (*a52_ptr_free)(a52_state_t * state);
+#define a52_free (*a52_ptr_free)
+
 #endif
 
+
 /**
  * liba52 - Copyright (C) Aaron Holtzman
  * released under the GPL license.
@@ -43,29 +79,6 @@
     a52_state_t* state;
     sample_t* samples;
 
-    /*
-     * virtual method table
-     *
-     * using this function table so the liba52 doesn't
-     * have to be really linked together with ffmpeg
-     * and might be linked in runtime - this allows binary
-     * distribution of ffmpeg library which doens't depend
-     * on liba52 library - but if user has it installed
-     * it will be used - user might install such library
-     * separately
-     */
-    void* handle;
-    a52_state_t* (*a52_init)(uint32_t mm_accel);
-    sample_t* (*a52_samples)(a52_state_t * state);
-    int (*a52_syncinfo)(uint8_t * buf, int * flags,
-			  int * sample_rate, int * bit_rate);
-    int (*a52_frame)(a52_state_t * state, uint8_t * buf, int * flags,
-		       sample_t * level, sample_t bias);
-    void (*a52_dynrng)(a52_state_t * state,
-			 sample_t (* call) (sample_t, void *), void * data);
-    int (*a52_block)(a52_state_t * state);
-    void (*a52_free)(a52_state_t * state);
-
 } AC3DecodeState;
 
 #ifdef CONFIG_A52BIN
@@ -73,46 +86,104 @@
 {
     void* f = dlsym(handle, symbol);
     if (!f)
-	fprintf(stderr, "A52 Decoder - function '%s' can't be resolved\n", symbol);
+        av_log(NULL, AV_LOG_ERROR, "A52 Decoder - function '%s' can't be resolved\n", symbol);
     return f;
 }
+
+static void unload_liba52(void);
+
+/**
+ * Check whether liba52 has been loaded. If not, returns a value < 0; zero else.
+ * If not, loads the library.
+ */
+static int check_liba52_loaded(void)
+{
+    if (liba52_loaded)
+        return 0;
+        
+    if (liba52_load_error)
+        return -1;
+    
+    liba52_handle = dlopen(liba52name, RTLD_LAZY);
+    if (!liba52_handle)
+    {
+        av_log(NULL, AV_LOG_ERROR, "A52 library %s could not be opened! \n%s\n", liba52name, dlerror());
+        liba52_load_error = 1;
+        return -1;
+    }
+  
+    a52_ptr_init = (a52_state_t* (*)(uint32_t)) dlsymm(liba52_handle, "a52_init");
+    a52_ptr_samples = (sample_t* (*)(a52_state_t*)) dlsymm(liba52_handle, "a52_samples");
+    a52_ptr_syncinfo = (int (*)(const uint8_t*, int*, int*, int*)) dlsymm(liba52_handle, "a52_syncinfo");
+    a52_ptr_frame = (int (*)(a52_state_t*, uint8_t*, int*, sample_t*, sample_t)) dlsymm(liba52_handle, "a52_frame");
+    a52_ptr_block = (int (*)(a52_state_t*)) dlsymm(liba52_handle, "a52_block");
+    a52_ptr_free = (void (*)(a52_state_t*)) dlsymm(liba52_handle, "a52_free");
+
+    if(!a52_init || !a52_samples || !a52_syncinfo || !a52_frame || !a52_block || !a52_free)
+    {
+        unload_liba52();
+        liba52_load_error = 1;
+        return -1;
+    }
+    
+    liba52_loaded = 1;
+    
+//    av_log(NULL, AV_LOG_INFO, "A52 library: Successfully loaded %s.\n", liba52name);
+    
+    return 0;
+}
+
+/** Unload the library, if loaded. */
+static void unload_liba52(void)
+{
+    dlclose(liba52_handle);
+    liba52_handle = 0;
+    a52_ptr_init = 0;
+    a52_ptr_samples = 0;
+    a52_ptr_syncinfo = 0;
+    a52_ptr_frame = 0;
+    a52_ptr_block = 0;
+    a52_ptr_free = 0;
+    
+//    av_log(NULL, AV_LOG_INFO, "A52 library: Unloaded %s.\n", liba52name);
+    
+    liba52_loaded = 0;
+}
+
 #endif
 
+
+/* For external usage. Forward to a52_syncinfo. Needed for parser.c . */
+int a52_syncinfo_ext(const uint8_t * buf, int * flags, int * sample_rate, int * bit_rate)
+{
+  int ret;
+  
+  ret = check_liba52_loaded();
+  if(ret < 0)
+  {
+//    av_log(NULL, AV_LOG_ERROR, "A52 library: a52_syncinfo: Couldn't load library, error.\n");
+    return 0;
+  }
+
+  return a52_syncinfo(buf, flags, sample_rate, bit_rate);
+}
+
 static int a52_decode_init(AVCodecContext *avctx)
 {
     AC3DecodeState *s = avctx->priv_data;
+    int ret;
 
 #ifdef CONFIG_A52BIN
-    s->handle = dlopen(liba52name, RTLD_LAZY);
-    if (!s->handle)
+    ret = check_liba52_loaded();
+    if(ret < 0)
     {
-	fprintf(stderr, "A52 library %s could not be opened! \n%s\n", liba52name, dlerror());
+	av_log(avctx, AV_LOG_ERROR, "A52 library %s could not be opened! \n%s\n", liba52name, dlerror());
         return -1;
     }
-    s->a52_init = (a52_state_t* (*)(uint32_t)) dlsymm(s->handle, "a52_init");
-    s->a52_samples = (sample_t* (*)(a52_state_t*)) dlsymm(s->handle, "a52_samples");
-    s->a52_syncinfo = (int (*)(uint8_t*, int*, int*, int*)) dlsymm(s->handle, "a52_syncinfo");
-    s->a52_frame = (int (*)(a52_state_t*, uint8_t*, int*, sample_t*, sample_t)) dlsymm(s->handle, "a52_frame");
-    s->a52_block = (int (*)(a52_state_t*)) dlsymm(s->handle, "a52_block");
-    s->a52_free = (void (*)(a52_state_t*)) dlsymm(s->handle, "a52_free");
-    if (!s->a52_init || !s->a52_samples || !s->a52_syncinfo
-        || !s->a52_frame || !s->a52_block || !s->a52_free)
-    {
-	dlclose(s->handle);
-        return -1;
-    }
-#else
-    /* static linked version */
-    s->handle = 0;
-    s->a52_init = a52_init;
-    s->a52_samples = a52_samples;
-    s->a52_syncinfo = a52_syncinfo;
-    s->a52_frame = a52_frame;
-    s->a52_block = a52_block;
-    s->a52_free = a52_free;
 #endif
-    s->state = s->a52_init(0); /* later use CPU flags */
-    s->samples = s->a52_samples(s->state);
+
+    s->state = a52_init(0); /* later use CPU flags */
+    s->samples = a52_samples(s->state);
     s->inbuf_ptr = s->inbuf;
     s->frame_size = 0;
 
@@ -173,7 +244,7 @@
             s->inbuf_ptr += len;
             buf_size -= len;
             if ((s->inbuf_ptr - s->inbuf) == HEADER_SIZE) {
-                len = s->a52_syncinfo(s->inbuf, &s->flags, &sample_rate, &bit_rate);
+                len = a52_syncinfo(s->inbuf, &s->flags, &sample_rate, &bit_rate);
                 if (len == 0) {
                     /* no sync found : move by one byte (inefficient, but simple!) */
                     memcpy(s->inbuf, s->inbuf + 1, HEADER_SIZE - 1);
@@ -213,14 +284,14 @@
             else
                 flags |= A52_ADJUST_LEVEL;
             level = 1;
-            if (s->a52_frame(s->state, s->inbuf, &flags, &level, 384)) {
+            if (a52_frame(s->state, s->inbuf, &flags, &level, 384)) {
             fail:
                 s->inbuf_ptr = s->inbuf;
                 s->frame_size = 0;
                 continue;
             }
             for (i = 0; i < 6; i++) {
-                if (s->a52_block(s->state))
+                if (a52_block(s->state))
                     goto fail;
                 float_to_int(s->samples, out_samples + i * 256 * avctx->channels, avctx->channels);
             }
@@ -236,10 +307,12 @@
 static int a52_decode_end(AVCodecContext *avctx)
 {
     AC3DecodeState *s = avctx->priv_data;
-    s->a52_free(s->state);
+    a52_free(s->state);
+
 #ifdef CONFIG_A52BIN
-    dlclose(s->handle);
+    unload_liba52();
 #endif
+
     return 0;
 }
 
--- ffmpegcvs-20050716.orig/libavcodec/parser.c	2005-06-11 20:06:25.000000000 +0200
+++ ffmpegcvs-20050716/libavcodec/parser.c	2005-06-11 20:06:40.000000000 +0200
@@ -673,8 +673,8 @@
 }
 
 #ifdef CONFIG_AC3
-extern int a52_syncinfo (const uint8_t * buf, int * flags,
-                         int * sample_rate, int * bit_rate);
+extern int a52_syncinfo_ext (const uint8_t * buf, int * flags,
+                             int * sample_rate, int * bit_rate);
 
 typedef struct AC3ParseContext {
     uint8_t inbuf[4096]; /* input buffer */
@@ -721,7 +721,7 @@
             s->inbuf_ptr += len;
             buf_size -= len;
             if ((s->inbuf_ptr - s->inbuf) == AC3_HEADER_SIZE) {
-                len = a52_syncinfo(s->inbuf, &s->flags, &sample_rate, &bit_rate);
+                len = a52_syncinfo_ext(s->inbuf, &s->flags, &sample_rate, &bit_rate);
                 if (len == 0) {
                     /* no sync found : move by one byte (inefficient, but simple!) */
                     memmove(s->inbuf, s->inbuf + 1, AC3_HEADER_SIZE - 1);