[libstagefright] fix -Wimplicit-int-float-conversion

IEEE754 single precision cannot precisely represent
INT32_MAX/UINT_MAX/RAND_MAX.

IEEE754 double precision cannot precisely represent INT64_MAX.

As such, implicit conversions from operations with floating point and
integral operands may result in a loss of precision.

Accept the imprecision with by making the existing implicit casts
explicit.

Bug: 139945549
Test: mm
Merged-in: Ic66b3d3bbac9e644e27ad8233018f24dfce3209f
Change-Id: Ic5a40abbccb1bf4d78475a6f3d1d2835df603d0a
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

cmds/stagefright/stagefright.cpp

@@ -304,7 +304,7 @@ static void playSource(sp<MediaSource> &source) {
             seekTimeUs = -1;
 
             if (shouldSeek) {
-                seekTimeUs = (rand() * (float)durationUs) / RAND_MAX;
+                seekTimeUs = (rand() * (float)durationUs) / (float)RAND_MAX;
                 options.setSeekTo(seekTimeUs);
 
                 printf("seeking to %" PRId64 " us (%.2f secs)\n",

media/libstagefright/ACodec.cpp

@@ -2403,7 +2403,7 @@ status_t ACodec::setOperatingRate(float rateFloat, bool isVideo) {
         }
         rate = (OMX_U32)(rateFloat * 65536.0f + 0.5f);
     } else {
-        if (rateFloat > UINT_MAX) {
+        if (rateFloat > static_cast<float>(UINT_MAX)) {
             return BAD_VALUE;
         }
         rate = (OMX_U32)(rateFloat);

media/libstagefright/MediaClock.cpp

@@ -281,7 +281,7 @@ void MediaClock::processTimers_l() {
             it = mTimers.erase(it);
         } else {
             if (mPlaybackRate != 0.0
-                && (double)diffMediaUs < INT64_MAX * (double)mPlaybackRate) {
+                && (double)diffMediaUs < (double)INT64_MAX * (double)mPlaybackRate) {
                 int64_t targetRealUs = diffMediaUs / (double)mPlaybackRate;
                 if (targetRealUs < nextLapseRealUs) {
                     nextLapseRealUs = targetRealUs;

media/libstagefright/Utils.cpp

@@ -1806,7 +1806,7 @@ void convertMessageToMetaData(const sp<AMessage> &msg, sp<MetaData> &meta) {
     if (msg->findInt32("frame-rate", &fps) && fps > 0) {
         meta->setInt32(kKeyFrameRate, fps);
     } else if (msg->findFloat("frame-rate", &fpsFloat)
-            && fpsFloat >= 1 && fpsFloat <= INT32_MAX) {
+            && fpsFloat >= 1 && static_cast<int32_t>(fpsFloat) <= INT32_MAX) {
         // truncate values to distinguish between e.g. 24 vs 23.976 fps
         meta->setInt32(kKeyFrameRate, (int32_t)fpsFloat);
     }

media/libstagefright/codecs/mp3dec/src/pv_mp3dec_fxd_op_c_equivalent.h

@@ -44,7 +44,7 @@ extern "C"
 #endif
 
 #include "pvmp3_audio_type_defs.h"
-#define Qfmt_31(a)   (Int32)((float)(a)*0x7FFFFFFF)
+#define Qfmt_31(a)   (Int32)((float)(a)*(float)0x7FFFFFFF)
 
 #define Qfmt15(x)   (Int16)((x)*((Int32)1<<15) + ((x)>=0?0.5F:-0.5F))
 

media/libstagefright/codecs/mp3dec/src/pvmp3_alias_reduction.cpp

@@ -169,7 +169,7 @@ void pvmp3_alias_reduction(int32 *input_buffer,         /* Ptr to spec values of
 
     int32 i, j;
 
-    *used_freq_lines = fxp_mul32_Q32(*used_freq_lines << 16, (int32)(0x7FFFFFFF / (float)18 - 1.0f)) >> 15;
+    *used_freq_lines = fxp_mul32_Q32(*used_freq_lines << 16, (int32)((float)0x7FFFFFFF / 18.0f - 1.0f)) >> 15;
 
 
     if (gr_info->window_switching_flag &&  gr_info->block_type == 2)

media/libstagefright/codecs/mp3dec/src/pvmp3_dct_9.cpp

@@ -77,7 +77,7 @@ Returns
 ; Include all pre-processor statements here. Include conditional
 ; compile variables also.
 ----------------------------------------------------------------------------*/
-#define Qfmt31(a)   (int32)((a)*(0x7FFFFFFF))
+#define Qfmt31(a)   (int32)((a)*((float)0x7FFFFFFF))
 
 #define cos_pi_9    Qfmt31( 0.93969262078591f)
 #define cos_2pi_9   Qfmt31( 0.76604444311898f)