avcodec/adpcmenc: Use smaller scope for some variables

This is to avoid unused variables warnings if the code for disabled
encoders is #if'ed away which will happen in a subsequent commit.
In case of buf it also avoids shadowing.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 54 insertions, 51 deletions

diff --git a/libavcodec/adpcmenc.c b/libavcodec/adpcmenc.c
index 2b5a606699..b95a9822e5 100644
--- a/libavcodec/adpcmenc.c
+++ b/libavcodec/adpcmenc.c
@@ -67,8 +67,6 @@ typedef struct ADPCMEncodeContext {
 static av_cold int adpcm_encode_init(AVCodecContext *avctx)
 {
     ADPCMEncodeContext *s = avctx->priv_data;
-    uint8_t *extradata;
-    int i;
 
     if (avctx->channels > 2) {
         av_log(avctx, AV_LOG_ERROR, "only stereo or mono is supported\n");
@@ -132,6 +130,8 @@ static av_cold int adpcm_encode_init(AVCodecContext *avctx)
         avctx->block_align = 34 * avctx->channels;
         break;
     case AV_CODEC_ID_ADPCM_MS:
+    {
+        uint8_t *extradata;
         /* each 16 bits sample gives one nibble
            and we have 7 bytes per channel overhead */
         avctx->frame_size = (s->block_size - 7 * avctx->channels) * 2 / avctx->channels + 2;
@@ -143,11 +143,12 @@ static av_cold int adpcm_encode_init(AVCodecContext *avctx)
         extradata = avctx->extradata;
         bytestream_put_le16(&extradata, avctx->frame_size);
         bytestream_put_le16(&extradata, 7); /* wNumCoef */
-        for (i = 0; i < 7; i++) {
+        for (int i = 0; i < 7; i++) {
             bytestream_put_le16(&extradata, ff_adpcm_AdaptCoeff1[i] * 4);
             bytestream_put_le16(&extradata, ff_adpcm_AdaptCoeff2[i] * 4);
         }
         break;
+    }
     case AV_CODEC_ID_ADPCM_YAMAHA:
         avctx->frame_size  = s->block_size * 2 / avctx->channels;
         avctx->block_align = s->block_size;
@@ -588,12 +589,11 @@ static int64_t adpcm_argo_compress_block(ADPCMChannelStatus *cs, PutBitContext *
 static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
                               const AVFrame *frame, int *got_packet_ptr)
 {
-    int n, i, ch, st, pkt_size, ret;
+    int st, pkt_size, ret;
     const int16_t *samples;
     int16_t **samples_p;
     uint8_t *dst;
     ADPCMEncodeContext *c = avctx->priv_data;
-    uint8_t *buf;
 
     samples = (const int16_t *)frame->data[0];
     samples_p = (int16_t **)frame->extended_data;
@@ -613,11 +613,9 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
     switch(avctx->codec->id) {
     case AV_CODEC_ID_ADPCM_IMA_WAV:
     {
-        int blocks, j;
-
-        blocks = (frame->nb_samples - 1) / 8;
+        int blocks = (frame->nb_samples - 1) / 8;
 
-        for (ch = 0; ch < avctx->channels; ch++) {
+        for (int ch = 0; ch < avctx->channels; ch++) {
             ADPCMChannelStatus *status = &c->status[ch];
             status->prev_sample = samples_p[ch][0];
             /* status->step_index = 0;
@@ -629,27 +627,28 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
 
         /* stereo: 4 bytes (8 samples) for left, 4 bytes for right */
         if (avctx->trellis > 0) {
+            uint8_t *buf;
             if (!FF_ALLOC_TYPED_ARRAY(buf, avctx->channels * blocks * 8))
                 return AVERROR(ENOMEM);
-            for (ch = 0; ch < avctx->channels; ch++) {
+            for (int ch = 0; ch < avctx->channels; ch++) {
                 adpcm_compress_trellis(avctx, &samples_p[ch][1],
                                        buf + ch * blocks * 8, &c->status[ch],
                                        blocks * 8, 1);
             }
-            for (i = 0; i < blocks; i++) {
-                for (ch = 0; ch < avctx->channels; ch++) {
+            for (int i = 0; i < blocks; i++) {
+                for (int ch = 0; ch < avctx->channels; ch++) {
                     uint8_t *buf1 = buf + ch * blocks * 8 + i * 8;
-                    for (j = 0; j < 8; j += 2)
+                    for (int j = 0; j < 8; j += 2)
                         *dst++ = buf1[j] | (buf1[j + 1] << 4);
                 }
             }
             av_free(buf);
         } else {
-            for (i = 0; i < blocks; i++) {
-                for (ch = 0; ch < avctx->channels; ch++) {
+            for (int i = 0; i < blocks; i++) {
+                for (int ch = 0; ch < avctx->channels; ch++) {
                     ADPCMChannelStatus *status = &c->status[ch];
                     const int16_t *smp = &samples_p[ch][1 + i * 8];
-                    for (j = 0; j < 8; j += 2) {
+                    for (int j = 0; j < 8; j += 2) {
                         uint8_t v = adpcm_ima_compress_sample(status, smp[j    ]);
                         v        |= adpcm_ima_compress_sample(status, smp[j + 1]) << 4;
                         *dst++ = v;
@@ -664,7 +663,7 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
         PutBitContext pb;
         init_put_bits(&pb, dst, pkt_size);
 
-        for (ch = 0; ch < avctx->channels; ch++) {
+        for (int ch = 0; ch < avctx->channels; ch++) {
             ADPCMChannelStatus *status = &c->status[ch];
             put_bits(&pb, 9, (status->prev_sample & 0xFFFF) >> 7);
             put_bits(&pb, 7,  status->step_index);
@@ -672,11 +671,11 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
                 uint8_t buf[64];
                 adpcm_compress_trellis(avctx, &samples_p[ch][0], buf, status,
                                        64, 1);
-                for (i = 0; i < 64; i++)
+                for (int i = 0; i < 64; i++)
                     put_bits(&pb, 4, buf[i ^ 1]);
                 status->prev_sample = status->predictor;
             } else {
-                for (i = 0; i < 64; i += 2) {
+                for (int i = 0; i < 64; i += 2) {
                     int t1, t2;
                     t1 = adpcm_ima_qt_compress_sample(status, samples_p[ch][i    ]);
                     t2 = adpcm_ima_qt_compress_sample(status, samples_p[ch][i + 1]);
@@ -696,8 +695,8 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
 
         av_assert0(avctx->trellis == 0);
 
-        for (i = 0; i < frame->nb_samples; i++) {
-            for (ch = 0; ch < avctx->channels; ch++) {
+        for (int i = 0; i < frame->nb_samples; i++) {
+            for (int ch = 0; ch < avctx->channels; ch++) {
                 put_bits(&pb, 4, adpcm_ima_qt_compress_sample(c->status + ch, *samples++));
             }
         }
@@ -712,8 +711,8 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
 
         av_assert0(avctx->trellis == 0);
 
-        for (n = frame->nb_samples / 2; n > 0; n--) {
-            for (ch = 0; ch < avctx->channels; ch++) {
+        for (int n = frame->nb_samples / 2; n > 0; n--) {
+            for (int ch = 0; ch < avctx->channels; ch++) {
                 put_bits(&pb, 4, adpcm_ima_alp_compress_sample(c->status + ch, *samples++));
                 put_bits(&pb, 4, adpcm_ima_alp_compress_sample(c->status + ch, samples[st]));
             }
@@ -725,11 +724,10 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
     }
     case AV_CODEC_ID_ADPCM_SWF:
     {
+        const int n = frame->nb_samples - 1;
         PutBitContext pb;
         init_put_bits(&pb, dst, pkt_size);
 
-        n = frame->nb_samples - 1;
-
         /* NB: This is safe as we don't have AV_CODEC_CAP_SMALL_LAST_FRAME. */
         av_assert0(n == 4095);
 
@@ -737,7 +735,7 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
         put_bits(&pb, 2, 2);    // set 4-bit flash adpcm format
 
         // init the encoder state
-        for (i = 0; i < avctx->channels; i++) {
+        for (int i = 0; i < avctx->channels; i++) {
             // clip step so it fits 6 bits
             c->status[i].step_index = av_clip_uintp2(c->status[i].step_index, 6);
             put_sbits(&pb, 16, samples[i]);
@@ -753,13 +751,13 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
                 adpcm_compress_trellis(avctx, samples + avctx->channels + 1,
                                        buf + n, &c->status[1], n,
                                        avctx->channels);
-            for (i = 0; i < n; i++) {
+            for (int i = 0; i < n; i++) {
                 put_bits(&pb, 4, buf[i]);
                 if (avctx->channels == 2)
                     put_bits(&pb, 4, buf[n + i]);
             }
         } else {
-            for (i = 1; i < frame->nb_samples; i++) {
+            for (int i = 1; i < frame->nb_samples; i++) {
                 put_bits(&pb, 4, adpcm_ima_compress_sample(&c->status[0],
                          samples[avctx->channels * i]));
                 if (avctx->channels == 2)
@@ -771,46 +769,47 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
         break;
     }
     case AV_CODEC_ID_ADPCM_MS:
-        for (i = 0; i < avctx->channels; i++) {
+        for (int i = 0; i < avctx->channels; i++) {
             int predictor = 0;
             *dst++ = predictor;
             c->status[i].coeff1 = ff_adpcm_AdaptCoeff1[predictor];
             c->status[i].coeff2 = ff_adpcm_AdaptCoeff2[predictor];
         }
-        for (i = 0; i < avctx->channels; i++) {
+        for (int i = 0; i < avctx->channels; i++) {
             if (c->status[i].idelta < 16)
                 c->status[i].idelta = 16;
             bytestream_put_le16(&dst, c->status[i].idelta);
         }
-        for (i = 0; i < avctx->channels; i++)
+        for (int i = 0; i < avctx->channels; i++)
             c->status[i].sample2= *samples++;
-        for (i = 0; i < avctx->channels; i++) {
+        for (int i = 0; i < avctx->channels; i++) {
             c->status[i].sample1 = *samples++;
             bytestream_put_le16(&dst, c->status[i].sample1);
         }
-        for (i = 0; i < avctx->channels; i++)
+        for (int i = 0; i < avctx->channels; i++)
             bytestream_put_le16(&dst, c->status[i].sample2);
 
         if (avctx->trellis > 0) {
-            n = avctx->block_align - 7 * avctx->channels;
-            if (!(buf = av_malloc(2 * n)))
+            const int n  = avctx->block_align - 7 * avctx->channels;
+            uint8_t *buf = av_malloc(2 * n);
+            if (!buf)
                 return AVERROR(ENOMEM);
             if (avctx->channels == 1) {
                 adpcm_compress_trellis(avctx, samples, buf, &c->status[0], n,
                                        avctx->channels);
-                for (i = 0; i < n; i += 2)
+                for (int i = 0; i < n; i += 2)
                     *dst++ = (buf[i] << 4) | buf[i + 1];
             } else {
                 adpcm_compress_trellis(avctx, samples,     buf,
                                        &c->status[0], n, avctx->channels);
                 adpcm_compress_trellis(avctx, samples + 1, buf + n,
                                        &c->status[1], n, avctx->channels);
-                for (i = 0; i < n; i++)
+                for (int i = 0; i < n; i++)
                     *dst++ = (buf[i] << 4) | buf[n + i];
             }
             av_free(buf);
         } else {
-            for (i = 7 * avctx->channels; i < avctx->block_align; i++) {
+            for (int i = 7 * avctx->channels; i < avctx->block_align; i++) {
                 int nibble;
                 nibble  = adpcm_ms_compress_sample(&c->status[ 0], *samples++) << 4;
                 nibble |= adpcm_ms_compress_sample(&c->status[st], *samples++);
@@ -819,22 +818,24 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
         }
         break;
     case AV_CODEC_ID_ADPCM_YAMAHA:
-        n = frame->nb_samples / 2;
+    {
+        int n = frame->nb_samples / 2;
         if (avctx->trellis > 0) {
-            if (!(buf = av_malloc(2 * n * 2)))
+            uint8_t *buf = av_malloc(2 * n * 2);
+            if (!buf)
                 return AVERROR(ENOMEM);
             n *= 2;
             if (avctx->channels == 1) {
                 adpcm_compress_trellis(avctx, samples, buf, &c->status[0], n,
                                        avctx->channels);
-                for (i = 0; i < n; i += 2)
+                for (int i = 0; i < n; i += 2)
                     *dst++ = buf[i] | (buf[i + 1] << 4);
             } else {
                 adpcm_compress_trellis(avctx, samples,     buf,
                                        &c->status[0], n, avctx->channels);
                 adpcm_compress_trellis(avctx, samples + 1, buf + n,
                                        &c->status[1], n, avctx->channels);
-                for (i = 0; i < n; i++)
+                for (int i = 0; i < n; i++)
                     *dst++ = buf[i] | (buf[n + i] << 4);
             }
             av_free(buf);
@@ -846,6 +847,7 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
                 *dst++  = nibble;
             }
         break;
+    }
     case AV_CODEC_ID_ADPCM_IMA_APM:
     {
         PutBitContext pb;
@@ -853,8 +855,8 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
 
         av_assert0(avctx->trellis == 0);
 
-        for (n = frame->nb_samples / 2; n > 0; n--) {
-            for (ch = 0; ch < avctx->channels; ch++) {
+        for (int n = frame->nb_samples / 2; n > 0; n--) {
+            for (int ch = 0; ch < avctx->channels; ch++) {
                 put_bits(&pb, 4, adpcm_ima_qt_compress_sample(c->status + ch, *samples++));
                 put_bits(&pb, 4, adpcm_ima_qt_compress_sample(c->status + ch, samples[st]));
             }
@@ -875,18 +877,19 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
         bytestream_put_le32(&dst, avctx->frame_size);
 
         if (avctx->trellis > 0) {
-            n = frame->nb_samples >> 1;
+            const int n  = frame->nb_samples >> 1;
+            uint8_t *buf = av_malloc(2 * n);
 
-            if (!(buf = av_malloc(2 * n)))
+            if (!buf)
                 return AVERROR(ENOMEM);
 
             adpcm_compress_trellis(avctx, samples, buf, &c->status[0], 2 * n, avctx->channels);
-            for (i = 0; i < n; i++)
+            for (int i = 0; i < n; i++)
                 bytestream_put_byte(&dst, (buf[2 * i] << 4) | buf[2 * i + 1]);
 
             samples += 2 * n;
             av_free(buf);
-        } else for (n = frame->nb_samples >> 1; n > 0; n--) {
+        } else for (int n = frame->nb_samples >> 1; n > 0; n--) {
             int nibble;
             nibble  = adpcm_ima_compress_sample(&c->status[0], *samples++) << 4;
             nibble |= adpcm_ima_compress_sample(&c->status[0], *samples++) & 0x0F;
@@ -906,7 +909,7 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
 
         av_assert0(frame->nb_samples == 32);
 
-        for (ch = 0; ch < avctx->channels; ch++) {
+        for (int ch = 0; ch < avctx->channels; ch++) {
             int64_t error  = INT64_MAX, tmperr = INT64_MAX;
             int     shift  = 2, flag = 0;
             int     saved1 = c->status[ch].sample1;
@@ -943,9 +946,9 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
         init_put_bits(&pb, dst, pkt_size);
 
         av_assert0(avctx->trellis == 0);
-        for (n = frame->nb_samples / 2; n > 0; n--) {
+        for (int n = frame->nb_samples / 2; n > 0; n--) {
             /* stereo: 1 byte (2 samples) for left, 1 byte for right */
-            for (ch = 0; ch < avctx->channels; ch++) {
+            for (int ch = 0; ch < avctx->channels; ch++) {
                 int t1, t2;
                 t1 = adpcm_ima_compress_sample(&c->status[ch], *samples++);
                 t2 = adpcm_ima_compress_sample(&c->status[ch], samples[st]);