fixes for new seeking algorithm

diff --git a/src/libFLAC/stream_decoder.c b/src/libFLAC/stream_decoder.c
index 9aca775..baa0fae 100644 (file)
--- a/src/libFLAC/stream_decoder.c
+++ b/src/libFLAC/stream_decoder.c
@@ -2928,17 +2928,23 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
        FLAC__int64 pos = -1;
        int i;
        unsigned approx_bytes_per_frame;
-       FLAC__bool needs_seek = true, first_seek = true;
+       FLAC__bool first_seek = true;
        const FLAC__uint64 total_samples = FLAC__stream_decoder_get_total_samples(decoder);
        const unsigned min_blocksize = decoder->private_->stream_info.data.stream_info.min_blocksize;
        const unsigned max_blocksize = decoder->private_->stream_info.data.stream_info.max_blocksize;
        const unsigned max_framesize = decoder->private_->stream_info.data.stream_info.max_framesize;
        const unsigned min_framesize = decoder->private_->stream_info.data.stream_info.min_framesize;
        /* take these from the current frame in case they've changed mid-stream */
-       const unsigned channels = FLAC__stream_decoder_get_channels(decoder);
-       const unsigned bps = FLAC__stream_decoder_get_bits_per_sample(decoder);
+       unsigned channels = FLAC__stream_decoder_get_channels(decoder);
+       unsigned bps = FLAC__stream_decoder_get_bits_per_sample(decoder);
        const FLAC__StreamMetadata_SeekTable *seek_table = decoder->private_->has_seek_table? &decoder->private_->seek_table.data.seek_table : 0;
 
+       /* use values from stream info if we didn't decode a frame */
+       if(channels == 0)
+               channels = decoder->private_->stream_info.data.stream_info.channels;
+       if(bps == 0)
+               bps = decoder->private_->stream_info.data.stream_info.bits_per_sample;
+
        /* we are just guessing here */
        if(max_framesize > 0)
                approx_bytes_per_frame = (max_framesize + min_framesize) / 2 + 1;
@@ -2966,6 +2972,8 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
        lower_bound_sample = 0;
        upper_bound = stream_length;
        upper_bound_sample = total_samples > 0 ? total_samples : target_sample;
+       if(upper_bound_sample == 0)
+               upper_bound_sample = 1;
 
        /*
         * Now we refine the bounds if we have a seektable with
@@ -3001,33 +3009,31 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
                        decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
                        return false;
                }
-               if(needs_seek) {
 #ifndef FLAC__INTEGER_ONLY_LIBRARY
 #if defined _MSC_VER || defined __MINGW32__
-                       /* with VC++ you have to spoon feed it the casting */
-                       pos = (FLAC__int64)lower_bound + (FLAC__int64)((FLAC__double)(FLAC__int64)(target_sample - lower_bound_sample) / (FLAC__double)(FLAC__int64)(upper_bound_sample - lower_bound_sample) * (FLAC__double)(FLAC__int64)(upper_bound - lower_bound)) - approx_bytes_per_frame;
+               /* with VC++ you have to spoon feed it the casting */
+               pos = (FLAC__int64)lower_bound + (FLAC__int64)((FLAC__double)(FLAC__int64)(target_sample - lower_bound_sample) / (FLAC__double)(FLAC__int64)(upper_bound_sample - lower_bound_sample) * (FLAC__double)(FLAC__int64)(upper_bound - lower_bound)) - approx_bytes_per_frame;
 #else
-                       pos = (FLAC__int64)lower_bound + (FLAC__int64)((FLAC__double)(target_sample - lower_bound_sample) / (FLAC__double)(upper_bound_sample - lower_bound_sample) * (FLAC__double)(upper_bound - lower_bound)) - approx_bytes_per_frame;
+               pos = (FLAC__int64)lower_bound + (FLAC__int64)((FLAC__double)(target_sample - lower_bound_sample) / (FLAC__double)(upper_bound_sample - lower_bound_sample) * (FLAC__double)(upper_bound - lower_bound)) - approx_bytes_per_frame;
 #endif
 #else
-                       /* a little less accurate: */
-                       if (upper_bound - lower_bound < 0xffffffff)
-                               pos = (FLAC__int64)lower_bound + (FLAC__int64)(((target_sample - lower_bound_sample) * (upper_bound - lower_bound)) / (upper_bound_sample - lower_bound_sample)) - approx_bytes_per_frame;
-                       else /* @@@ WATCHOUT, ~2TB limit */
-                               pos = (FLAC__int64)lower_bound + (FLAC__int64)((((target_sample - lower_bound_sample)>>8) * ((upper_bound - lower_bound)>>8)) / ((upper_bound_sample - lower_bound_sample)>>16)) - approx_bytes_per_frame;
+               /* a little less accurate: */
+               if(upper_bound - lower_bound < 0xffffffff)
+                       pos = (FLAC__int64)lower_bound + (FLAC__int64)(((target_sample - lower_bound_sample) * (upper_bound - lower_bound)) / (upper_bound_sample - lower_bound_sample)) - approx_bytes_per_frame;
+               else /* @@@ WATCHOUT, ~2TB limit */
+                       pos = (FLAC__int64)lower_bound + (FLAC__int64)((((target_sample - lower_bound_sample)>>8) * ((upper_bound - lower_bound)>>8)) / ((upper_bound_sample - lower_bound_sample)>>16)) - approx_bytes_per_frame;
 #endif
-                       if(pos >= (FLAC__int64)upper_bound)
-                               pos = (FLAC__int64)upper_bound - 1;
-                       if(pos < (FLAC__int64)lower_bound)
-                               pos = (FLAC__int64)lower_bound;
-                       if(decoder->private_->seek_callback(decoder, (FLAC__uint64)pos, decoder->private_->client_data) != FLAC__STREAM_DECODER_SEEK_STATUS_OK) {
-                               decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
-                               return false;
-                       }
-                       if(!FLAC__stream_decoder_flush(decoder)) {
-                               /* above call sets the state for us */
-                               return false;
-                       }
+               if(pos >= (FLAC__int64)upper_bound)
+                       pos = (FLAC__int64)upper_bound - 1;
+               if(pos < (FLAC__int64)lower_bound)
+                       pos = (FLAC__int64)lower_bound;
+               if(decoder->private_->seek_callback(decoder, (FLAC__uint64)pos, decoder->private_->client_data) != FLAC__STREAM_DECODER_SEEK_STATUS_OK) {
+                       decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
+                       return false;
+               }
+               if(!FLAC__stream_decoder_flush(decoder)) {
+                       /* above call sets the state for us */
+                       return false;
                }
                /* Now we need to get a frame.  First we need to reset our
                 * unparseable_frame_count; if we get too many unparseable
@@ -3053,7 +3059,7 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
                this_frame_sample = decoder->private_->last_frame.header.number.sample_number;
 
                if (!decoder->private_->samples_decoded || (this_frame_sample + decoder->private_->last_frame.header.blocksize >= upper_bound_sample && !first_seek)) {
-                       if (pos == (FLAC__int64)lower_bound || !needs_seek) {
+                       if (pos == (FLAC__int64)lower_bound) {
                                decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
                                return false;
                        }
@@ -3072,8 +3078,6 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
 
                FLAC__ASSERT(decoder->private_->last_frame.header.number_type == FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER);
 
-               approx_bytes_per_frame = decoder->private_->last_frame.header.blocksize * channels * bps/8 + 64;
-
                /* we need to narrow the search */
                if(target_sample < this_frame_sample) {
                        upper_bound_sample = this_frame_sample + decoder->private_->last_frame.header.blocksize;
@@ -3081,19 +3085,17 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
                                decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
                                return false;
                        }
+                       approx_bytes_per_frame = 2 * (upper_bound - pos) / 3 + 16;
                }
                else {
                        /* target_sample >= this_frame_sample + this frame's blocksize */
 
-                       /* we are close, continue in decoding next frames */
-                       if(target_sample < this_frame_sample + 4 * decoder->private_->last_frame.header.blocksize)
-                               needs_seek = false;
-                       
                        lower_bound_sample = this_frame_sample + decoder->private_->last_frame.header.blocksize;
                        if(!FLAC__stream_decoder_get_decode_position(decoder, &lower_bound)) {
                                decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
                                return false;
                        }
+                       approx_bytes_per_frame = 2 * (lower_bound - pos) / 3 + 16;
                }
        }