Allow float values for libmp3lame quality.

Patch by James Darnley, james D darnley A gmail

Originally committed as revision 25128 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -2714,7 +2714,7 @@ enabled libdirac   && add_cflags $(pkg-config --cflags dirac) &&
                       require  libdirac libdirac_encoder/dirac_encoder.h dirac_encoder_init $(pkg-config --libs dirac)
 enabled libfaac    && require2 libfaac "stdint.h faac.h" faacEncGetVersion -lfaac
 enabled libgsm     && require  libgsm gsm/gsm.h gsm_create -lgsm
-enabled libmp3lame && require  libmp3lame lame/lame.h lame_init -lmp3lame
+enabled libmp3lame && require  libmp3lame lame/lame.h hip_decode_init -lmp3lame
 enabled libnut     && require  libnut libnut.h nut_demuxer_init -lnut
 enabled libopencore_amrnb  && require libopencore_amrnb opencore-amrnb/interf_dec.h Decoder_Interface_init -lopencore-amrnb
 enabled libopencore_amrwb  && require libopencore_amrwb opencore-amrwb/dec_if.h D_IF_init -lopencore-amrwb

libavcodec/libmp3lame.c

@@ -61,7 +61,8 @@ static av_cold int MP3lame_encode_init(AVCodecContext *avctx)
     if(avctx->flags & CODEC_FLAG_QSCALE) {
         lame_set_brate(s->gfp, 0);
         lame_set_VBR(s->gfp, vbr_default);
-        lame_set_VBR_q(s->gfp, avctx->global_quality / (float)FF_QP2LAMBDA);
+        /* requires lame 3.98 or later */
+        lame_set_VBR_quality(s->gfp, avctx->global_quality/(float)FF_QP2LAMBDA);
     }
     lame_set_bWriteVbrTag(s->gfp,0);
     lame_set_disable_reservoir(s->gfp, avctx->flags2 & CODEC_FLAG2_BIT_RESERVOIR ? 0 : 1);