avoid link-time dependency to libavcodec

it has lots of lots of deps, and we want to run on barebone systems

diff --git a/configure b/configure
index 314cd95..9af719f 100755 (executable)
--- a/configure
+++ b/configure
@@ -280,7 +280,7 @@ check_libavcodec()
   #include <libavcodec/avcodec.h>
   void main() { avcodec_decode_audio3(0, 0, 0, 0); }
 EOF
-  compile_binary "$@" -lavcodec
+  compile_object "$@"
 }
 
 #MAIN_LDLIBS="$MAIN_LDLIBS -lz"
@@ -291,7 +291,11 @@ check_libpng || fail "please install libpng (libpng-dev)"
 
 if check_libavcodec; then
   have_libavcodec="yes"
-  MAIN_LDLIBS="-lavcodec $MAIN_LDLIBS"
+  # add -ldl if needed
+  case "$MAIN_LDLIBS" in
+    *"-ldl"*) ;;
+    *) MAIN_LDLIBS="-ldl $MAIN_LDLIBS" ;;
+  esac
 fi
 
 # find what audio support we can compile

diff --git a/platform/common/mp3_libavcodec.c b/platform/common/mp3_libavcodec.c
index 833b30b..3c93dfb 100644 (file)
--- a/platform/common/mp3_libavcodec.c
+++ b/platform/common/mp3_libavcodec.c
@@ -10,6 +10,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <libavcodec/avcodec.h>
+#include <dlfcn.h>
 
 #include <pico/pico_int.h>
 #include "../libpicofe/lprintf.h"
@@ -17,6 +18,12 @@
 
 static AVCodecContext *ctx;
 
+/* avoid compile time linking to libavcodec due to huge list of it's deps..
+ * we also use this old API as newer one is not available on pandora */
+void (*p_av_init_packet)(AVPacket *pkt);
+int (*p_avcodec_decode_audio3)(AVCodecContext *avctx, int16_t *samples,
+       int *frame_size_ptr, AVPacket *avpkt);
+
 int mp3dec_decode(FILE *f, int *file_pos, int file_len)
 {
        unsigned char input_buf[2 * 1024];
@@ -27,7 +34,7 @@ int mp3dec_decode(FILE *f, int *file_pos, int file_len)
        int offset;
        int len;
 
-       av_init_packet(&avpkt);
+       p_av_init_packet(&avpkt);
 
        do
        {
@@ -60,8 +67,13 @@ int mp3dec_decode(FILE *f, int *file_pos, int file_len)
                avpkt.data = input_buf + offset;
                avpkt.size = frame_size;
                bytes_out = sizeof(cdda_out_buffer);
+#if LIBAVCODEC_VERSION_MAJOR < 53
+               // stupidity in v52: enforces this size even when
+               // it doesn't need/use that much at all
+               bytes_out = AVCODEC_MAX_AUDIO_FRAME_SIZE;
+#endif
 
-               len = avcodec_decode_audio3(ctx, cdda_out_buffer,
+               len = p_avcodec_decode_audio3(ctx, cdda_out_buffer,
                        &bytes_out, &avpkt);
                if (len <= 0) {
                        lprintf("mp3 decode err (%i/%i) %i\n",
@@ -81,12 +93,45 @@ int mp3dec_decode(FILE *f, int *file_pos, int file_len)
 
 int mp3dec_start(void)
 {
+       void (*avcodec_register_all)(void);
+       AVCodec *(*avcodec_find_decoder)(enum CodecID id);
+       AVCodecContext *(*avcodec_alloc_context)(void);
+       int (*avcodec_open)(AVCodecContext *avctx, AVCodec *codec);
+       void (*av_free)(void *ptr);
        AVCodec *codec;
+       void *soh;
        int ret;
 
        if (ctx != NULL)
                return 0;
 
+       // either v52 or v53 should be ok
+       soh = dlopen("libavcodec.so.52", RTLD_NOW);
+       if (soh == NULL)
+               soh = dlopen("libavcodec.so.53", RTLD_NOW);
+       if (soh == NULL) {
+               lprintf("mp3dec: load libavcodec.so: %s\n", dlerror());
+               return -1;
+       }
+
+       avcodec_register_all = dlsym(soh, "avcodec_register_all");
+       avcodec_find_decoder = dlsym(soh, "avcodec_find_decoder");
+       avcodec_alloc_context = dlsym(soh, "avcodec_alloc_context");
+       avcodec_open = dlsym(soh, "avcodec_open");
+       av_free = dlsym(soh, "av_free");
+       p_av_init_packet = dlsym(soh, "av_init_packet");
+       p_avcodec_decode_audio3 = dlsym(soh, "avcodec_decode_audio3");
+
+       if (avcodec_register_all == NULL || avcodec_find_decoder == NULL
+           || avcodec_alloc_context == NULL || avcodec_open == NULL
+           || av_free == NULL
+           || p_av_init_packet == NULL || p_avcodec_decode_audio3 == NULL)
+       {
+               lprintf("mp3dec: missing symbol(s) in libavcodec.so\n");
+               dlclose(soh);
+               return -1;
+       }
+
        // init decoder
 
        //avcodec_init();