Add ffmpeg example (#61)

ffmpeg-examples/run.sh

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+
+set -ex
+
+if [ ! -d ./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20 ]; then
+  echo "Please download the pre-trained model for testing."
+  echo "You can refer to"
+  echo ""
+  echo "https://k2-fsa.github.io/sherpa/onnx/pretrained_models/zipformer-transducer-models.html#sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20-bilingual-chinese-english"
+  echo "for help"
+  exit 1
+fi
+
+if [[ ! -f ../build/lib/libsherpa-onnx-core.a && ! -f ../build/lib/libsherpa-onnx-core.dylib  && ! -f ../build/lib/libsherpa-onnx-core.so ]]; then
+  echo "Please build sherpa-onnx first. You can use"
+  echo ""
+  echo "  cd /path/to/sherpa-onnx"
+  echo "  mkdir build"
+  echo "  cd build"
+  echo "  cmake .."
+  echo "  make -j4"
+  exit 1
+fi
+
+if [ ! -f ./sherpa-onnx-ffmpeg ]; then
+  make
+fi
+
+../ffmpeg-examples/sherpa-onnx-ffmpeg \
+  ./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/tokens.txt \
+  ./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/encoder-epoch-99-avg-1.onnx \
+  ./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/decoder-epoch-99-avg-1.onnx \
+  ./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/joiner-epoch-99-avg-1.onnx \
+  ./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/test_wavs/4.wav
+
+echo "Decoding a URL"
+
+../ffmpeg-examples/sherpa-onnx-ffmpeg \
+  ./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/tokens.txt \
+  ./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/encoder-epoch-99-avg-1.onnx \
+  ./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/decoder-epoch-99-avg-1.onnx \
+  ./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/joiner-epoch-99-avg-1.onnx \
+  https://huggingface.co/csukuangfj/sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/resolve/main/test_wavs/4.wav