Cosmetic change aimed at making it easier to see how bits are consumed

[ffmpeg] / libavcodec / alac.c

diff --git a/libavcodec/alac.c b/libavcodec/alac.c
index aa055c691d6c5b48065370f1ffe9f58fc02a7337..1817161160817ace60fcf0bfd79cd0836b229fa4 100644 (file)
--- a/libavcodec/alac.c
+++ b/libavcodec/alac.c
@@ -115,6 +115,10 @@ static int alac_set_info(ALACContext *alac)
     alac->setinfo_max_samples_per_frame = bytestream_get_be32(&ptr);
     ptr++;                          /* ??? */
     alac->setinfo_sample_size           = *ptr++;
+    if (alac->setinfo_sample_size > 32) {
+        av_log(alac->avctx, AV_LOG_ERROR, "setinfo_sample_size too large\n");
+        return -1;
+    }
     alac->setinfo_rice_historymult      = *ptr++;
     alac->setinfo_rice_initialhistory   = *ptr++;
     alac->setinfo_rice_kmodifier        = *ptr++;
@@ -199,7 +203,8 @@ static void bastardized_rice_decompress(ALACContext *alac,
 
         /* special case: there may be compressed blocks of 0 */
         if ((history < 128) && (output_count+1 < output_size)) {
-            int block_size, k;
+            int k;
+            unsigned int block_size;
 
             sign_modifier = 1;
 
@@ -208,6 +213,10 @@ static void bastardized_rice_decompress(ALACContext *alac,
             block_size= decode_scalar(&alac->gb, k, rice_kmodifier, 16);
 
             if (block_size > 0) {
+                if(block_size >= output_size - output_count){
+                    av_log(alac->avctx, AV_LOG_ERROR, "invalid zero block size of %d %d %d\n", block_size, output_size, output_count);
+                    block_size= output_size - output_count - 1;
+                }
                 memset(&output_buffer[output_count+1], 0, block_size * 4);
                 output_count += block_size;
             }
@@ -400,9 +409,9 @@ static int alac_decode_frame(AVCodecContext *avctx,
     ALACContext *alac = avctx->priv_data;
 
     int channels;
-    int32_t outputsamples;
+    unsigned int outputsamples;
     int hassize;
-    int readsamplesize;
+    unsigned int readsamplesize;
     int wasted_bytes;
     int isnotcompressed;
     uint8_t interlacing_shift;
@@ -452,12 +461,25 @@ static int alac_decode_frame(AVCodecContext *avctx,
 
     if (hassize) {
         /* now read the number of samples as a 32bit integer */
-        outputsamples = get_bits(&alac->gb, 32);
+        outputsamples = get_bits_long(&alac->gb, 32);
+        if(outputsamples > alac->setinfo_max_samples_per_frame){
+            av_log(avctx, AV_LOG_ERROR, "outputsamples %d > %d\n", outputsamples, alac->setinfo_max_samples_per_frame);
+            return -1;
+        }
     } else
         outputsamples = alac->setinfo_max_samples_per_frame;
 
+    if(outputsamples > *outputsize / alac->bytespersample){
+        av_log(avctx, AV_LOG_ERROR, "sample buffer too small\n");
+        return -1;
+    }
+
     *outputsize = outputsamples * alac->bytespersample;
     readsamplesize = alac->setinfo_sample_size - (wasted_bytes * 8) + channels - 1;
+    if (readsamplesize > MIN_CACHE_BITS) {
+        av_log(avctx, AV_LOG_ERROR, "readsamplesize too big (%d)\n", readsamplesize);
+        return -1;
+    }
 
     if (!isnotcompressed) {
         /* so it is compressed */
@@ -517,37 +539,22 @@ static int alac_decode_frame(AVCodecContext *avctx,
         }
     } else {
         /* not compressed, easy case */
-        if (alac->setinfo_sample_size <= 16) {
-            int i, chan;
-            for (chan = 0; chan < channels; chan++)
-                for (i = 0; i < outputsamples; i++) {
-                    int32_t audiobits;
+        int i, chan;
+        for (i = 0; i < outputsamples; i++)
+            for (chan = 0; chan < channels; chan++) {
+                int32_t audiobits;
 
-                    audiobits = get_bits(&alac->gb, alac->setinfo_sample_size);
-                    audiobits = extend_sign32(audiobits, readsamplesize);
+                audiobits = get_bits_long(&alac->gb, alac->setinfo_sample_size);
+                audiobits = extend_sign32(audiobits, alac->setinfo_sample_size);
 
-                    alac->outputsamples_buffer[chan][i] = audiobits;
-                }
-        } else {
-            int i, chan;
-            for (chan = 0; chan < channels; chan++)
-                for (i = 0; i < outputsamples; i++) {
-                    int32_t audiobits;
-
-                    audiobits = get_bits(&alac->gb, 16);
-                    /* special case of sign extension..
-                     * as we'll be ORing the low 16bits into this */
-                    audiobits = audiobits << 16;
-                    audiobits = audiobits >> (32 - alac->setinfo_sample_size);
-                    audiobits |= get_bits(&alac->gb, alac->setinfo_sample_size - 16);
-
-                    alac->outputsamples_buffer[chan][i] = audiobits;
-                }
-        }
+                alac->outputsamples_buffer[chan][i] = audiobits;
+            }
         /* wasted_bytes = 0; */
         interlacing_shift = 0;
         interlacing_leftweight = 0;
     }
+    if (get_bits(&alac->gb, 3) != 7)
+        av_log(avctx, AV_LOG_ERROR, "Error : Wrong End Of Frame\n");
 
     switch(alac->setinfo_sample_size) {
     case 16:
@@ -577,6 +584,9 @@ static int alac_decode_frame(AVCodecContext *avctx,
         break;
     }
 
+    if (input_buffer_size * 8 - get_bits_count(&alac->gb) > 8)
+        av_log(avctx, AV_LOG_ERROR, "Error : %d bits left\n", input_buffer_size * 8 - get_bits_count(&alac->gb));
+
     return input_buffer_size;
 }
 
@@ -588,6 +598,7 @@ static av_cold int alac_decode_init(AVCodecContext * avctx)
 
     alac->numchannels = alac->avctx->channels;
     alac->bytespersample = (avctx->bits_per_sample / 8) * alac->numchannels;
+    avctx->sample_fmt = SAMPLE_FMT_S16;
 
     return 0;
 }
@@ -614,4 +625,5 @@ AVCodec alac_decoder = {
     NULL,
     alac_decode_close,
     alac_decode_frame,
+    .long_name = NULL_IF_CONFIG_SMALL("ALAC (Apple Lossless Audio Codec)"),
 };