Cumulative patch to fix ffmpeg incomatibility in lame_encode_flush()

(for details see FFMPEG bug 803: https://roundup.ffmpeg.org/roundup/ffmpeg/issue803, 

 LAME bug 2553863: http://sourceforge.net/tracker/?func=detail&aid=2553863&group_id=290&atid=100290)

Revision 1.323.2.7 (Mon Mar 30 19:48:00 2009 UTC  by robert)

 ensure we padd at least 288 samples

Revision 1.323.2.6 (Sun Mar 29 14:43:22 2009 UTC   by robert)

 workaround for FFMPEG bug, which uses to call lame_encode_flush more than once in loop

Revision 1.323.2.5 (Sat Mar 28 22:09:45 2009 UTC   by robert)

 avoid extra frame at end

Revision 1.323.2.4 (Sun Jan 18 15:44:27 2009 UTC   by robert)

 replacing C++ style comments by C style comments

--- ./libmp3lame/lame.c	2009-07-28 19:52:17 +0400

+++ ./libmp3lame/lame.c	2009-03-30 23:48:00 +0400

@@ -1472,6 +1476,27 @@

 }

+static int

+calcNeeded(lame_global_flags* gfp)

+{

+    int mf_needed;

+    /* some sanity checks */

+#if ENCDELAY < MDCTDELAY

+# error ENCDELAY is less than MDCTDELAY, see encoder.h

+#endif

+#if FFTOFFSET > BLKSIZE

+# error FFTOFFSET is greater than BLKSIZE, see encoder.h

+#endif

+

+    mf_needed = BLKSIZE + gfp->framesize - FFTOFFSET; /* amount needed for FFT */

+    /*mf_needed = Max(mf_needed, 286 + 576 * (1 + gfc->mode_gr)); */

+    mf_needed = Max(mf_needed, 512 + gfp->framesize - 32);

+

+    assert(MFSIZE >= mf_needed);

+    

+    return mf_needed;

+}

+

 /*

  * THE MAIN LAME ENCODING INTERFACE

  * mt 3/00

@@ -1555,20 +1580,7 @@

         }

     }

-

-    /* some sanity checks */

-#if ENCDELAY < MDCTDELAY

-# error ENCDELAY is less than MDCTDELAY, see encoder.h

-#endif

-#if FFTOFFSET > BLKSIZE

-# error FFTOFFSET is greater than BLKSIZE, see encoder.h

-#endif

-

-    mf_needed = BLKSIZE + gfp->framesize - FFTOFFSET; /* amount needed for FFT */

-    /*mf_needed = Max(mf_needed, 286 + 576 * (1 + gfc->mode_gr)); */

-    mf_needed = Max(mf_needed, 512 + gfp->framesize - 32);

-

-    assert(MFSIZE >= mf_needed);

+    mf_needed = calcNeeded(gfp);

     mfbuf[0] = gfc->mfbuf[0];

     mfbuf[1] = gfc->mfbuf[1];

@@ -1602,6 +1614,13 @@

         /* update mfbuf[] counters */

         gfc->mf_size += n_out;

         assert(gfc->mf_size <= MFSIZE);

+

+        /* lame_encode_flush may have set gfc->mf_sample_to_encode to 0

+         * so we have to reinitialize it here when that happened.

+         */

+        if (gfc->mf_samples_to_encode < 1) {

+            gfc->mf_samples_to_encode = ENCDELAY + POSTDELAY;

+        }

         gfc->mf_samples_to_encode += n_out;

@@ -1926,24 +1945,36 @@

     /* we always add POSTDELAY=288 padding to make sure granule with real

      * data can be complety decoded (because of 50% overlap with next granule */

-    int     end_padding = POSTDELAY;

-    int     pad_out_samples;

+    int     end_padding;

     int     frames_left;

-    int     samples_to_encode = gfc->mf_samples_to_encode;

+    int     samples_to_encode = gfc->mf_samples_to_encode - POSTDELAY+288;

+    int     mf_needed = calcNeeded(gfp);

+    /* Was flush already called? */

+    if (gfc->mf_samples_to_encode < 1) {

+        return 0;

+    }

     memset(buffer, 0, sizeof(buffer));

     mp3count = 0;

-    

+

     if (gfp->in_samplerate != gfp->out_samplerate) {

         /* delay due to resampling; needs to be fixed, if resampling code gets changed */

         samples_to_encode += 16.*gfp->out_samplerate/gfp->in_samplerate;

     }

-    pad_out_samples = gfp->framesize - (samples_to_encode % gfp->framesize);

-    end_padding += pad_out_samples;

+    end_padding = gfp->framesize - (samples_to_encode % gfp->framesize);

+    gfp->encoder_padding = end_padding;

-    frames_left = (samples_to_encode + pad_out_samples) / gfp->framesize;

-    while (frames_left > 0) {

+    frames_left = (samples_to_encode + end_padding) / gfp->framesize;

+

+    /* send in a frame of 0 padding until all internal sample buffers are flushed */

+    while (frames_left > 0 && imp3 >= 0) {

+        int bunch = mf_needed-gfc->mf_size;

         int frame_num = gfp->frameNum;

+        

+        bunch *= gfp->in_samplerate;

+        bunch /= gfp->out_samplerate;

+        if (bunch > 1152) bunch = 1152;

+        if (bunch < 1) bunch = 1;

         mp3buffer_size_remaining = mp3buffer_size - mp3count;

@@ -1951,22 +1982,23 @@

         if (mp3buffer_size == 0)

             mp3buffer_size_remaining = 0;

-        /* send in a frame of 0 padding until all internal sample buffers

-         * are flushed

-         */

-        imp3 = lame_encode_buffer(gfp, buffer[0], buffer[1], 32,

+        imp3 = lame_encode_buffer(gfp, buffer[0], buffer[1], bunch,

                                   mp3buffer, mp3buffer_size_remaining);

-        if (frame_num != gfp->frameNum) {

-            --frames_left;

-        }

-        if (imp3 < 0) {

-            /* some type of fatal error */

-            return imp3;

-        }

         mp3buffer += imp3;

         mp3count += imp3;

+        frames_left -= (frame_num != gfp->frameNum) ? 1 : 0;

     }

+    /* Set gfc->mf_samples_to_encode to 0, so we may detect

+     * and break loops calling it more than once in a row.

+     */

+    gfc->mf_samples_to_encode = 0;

+

+    if (imp3 < 0) {

+        /* some type of fatal error */

+        return imp3;

+    }

+

     mp3buffer_size_remaining = mp3buffer_size - mp3count;

     /* if user specifed buffer size = 0, dont check size */

     if (mp3buffer_size == 0)

@@ -1997,7 +2029,6 @@

         }

         mp3count += imp3;

     }

-    gfp->encoder_padding = end_padding;

 #if 0

     {

         int const ed = gfp->encoder_delay;

@@ -2011,6 +2042,8 @@

         MSGF(gfc, "encoder padding=%d\n", ep);

         MSGF(gfc, "sample count=%d (%g)\n", ns, gfp->in_samplerate*duration);

         MSGF(gfc, "duration=%g sec\n", duration);

+        MSGF(gfc, "mf_size=%d\n",gfc->mf_size);

+        MSGF(gfc, "mf_samples_to_encode=%d\n",gfc->mf_samples_to_encode);

     }

 #endif

     return mp3count;

@@ -2052,7 +2085,12 @@

 /* flush internal mp3 buffers, and free internal buffers         */

 /*****************************************************************/

 #if DEPRECATED_OR_OBSOLETE_CODE_REMOVED

+/* OBSOLETE */

+int CDECL

+lame_encode_finish(lame_global_flags * gfp, unsigned char *mp3buffer, int mp3buffer_size);

 #else

+#endif

+

 int

 lame_encode_finish(lame_global_flags * gfp, unsigned char *mp3buffer, int mp3buffer_size)

 {

@@ -2062,7 +2100,6 @@

     return ret;

 }

-#endif

 /*****************************************************************/

 /* write VBR Xing header, and ID3 version 1 tag, if asked for    */