works with track/upload but not with song/identify

Hi, I've captured 30 seconds of a music using ffmpeg in wav format.

My problem is that the music is recognized by using track/upload with this command :

curl -F "api_key=XXX" -F "filetype=wav" -F "track=@sound.wav""http://developer.echonest.com/api/v4/track/upload"> info.txt

info.txt contains :

{"response": {"status": {"version": "4.2", "code": 0, "message": "Success"}, "track": {"status": "pending", "song_id": "SOBFMHC12A6D4F9401", "audio_md5": null, "artist": "Daft Punk", "title": "High Life", "analyzer_version": "3.2.2", "release": "Discovery", "artist_id": "ARF8HTQ1187B9AE693", "bitrate": 1411, "id": "TRVPIUV144F9F9EFB1", "samplerate": 44100, "md5": "e00957509a255c5096551d3a09591caa"}}}

but when I used ENMFP_codegen using that command :

test sound.wav > code.txt

and then used song/identify using that command :

curl -F "api_key=XXX" -F "query=@json_string.json""http://developer.echonest.com/api/v4/song/identify"> info.txt

with json_string.json :

{
  "metadata": {
  },
  "code": "eJyVlwmSZCsIRbeUiONyHPe_hH-uma-ix9_dFVH4REC4IJqv1_0LHRIjJGvaJkT_r8WC2Ya4SELEsr4qgtZEhngTXnh1EX3JXnAshIhIyIiEKl7TV6-QGSBbwgfiKL6c_5f7JQh7Qs61mxcReeUDe74lfC5hGg2jMVyCXMzIxaaAOlbiZprkVZKIInilhFrKmE8FK6lqoUlE8aYtkTMFBp_ZEM6OSI6s5qSFLF7BQK4SGSLCIC_JHQwURVQESQnIlSRe0lT-FeFXhEGZWt2oFQVThEYV2DWzWrVHHSLKhzZ7Vck1U56chRaRa4qrZcw3wdTGzaK-Fipto9FfiPQAr0fUusx3wSSUIFrVHl0Y9IPI0B5DSRnK5RBqQxkcTatK_JjiKfIprKZSOAXTVIBT5qd8mZJbQmMpC0sBLsG-BPtSgEvQrYPINqZbiO8ioi13R26rXo42OgF7R5EfwXkqGqdrqmjORONQJUZlQjBlZBlSLtkQ_DPggOCf4TRkiXfVgNjMVPsUv1nEimURqVnTF4CZTX3t_rIAuqbiN8Vncs9C0QJYmVC3sLR6kHPQMpdXnkSocfPGvt61MPQlo04RUtxsGYO-QNciybNINVnMWgAhUz4tNjRU8nirBe0WOSSWhEFyEWGQFEeSmkre0kAjLU03q1lBZxdR0Kp2y1kL8i-TBXDQlCqxoqALsZryZCpvK4q8FNTKEKE2rBzxFEzlVFgNaiCOWqXnWFUwVVjVJp7yUZWPSrqtCdPGEbIm4aY9mgBrnAhrykIbWlXeusx3xatCt875MBW6qeVYVyq6IO7KdFeSVeM2ZH4oH0NBD1kegnMov2NhYCgfQ3BO5WOylc2gadSXUjGrpgphqkBU8vRFjE6K2pbiWGTTZx-pzM54Ql-JpnrCYJ5zIkud-Wqc5_AKzGWYvDD3sV6AFBj3ibbvWHAutzv6bq0zUhenZ9JVZsLtJv6B6a3CL5OC3xkmvSWG06oRPt4NJxmktsgeZT_e9mr8sgf2ssfJrDlFmfC6rV27cfuPduFfu-jRfq7dmgt82c3W_tUu8b79TXGfhL8XLyUnPHjV1_jg9cbpjVerX3hlFz7M8QN_koSuPynWxx_8eHDzuj64_U981y5M8Hvsbnvs_gI_8vLE2U74xPk_ecHfJy8pPHn5xl_0H393fvKMH_-K2x3vAfoeP7Z846f6OO96-1V9IP_lx0mPH-D9m7iwc-N6x8NB_BNOY12csAPON65g8of6OvGprw_u39TXn_L5Ez71Cx-q8MGn_ozP7BefsNIJFXx-ONeXP-78O_4d4X-tc0N-1rk-Hz2u0t_x_2Tvsx6svvuL75rl7PR4On138cQCJa6iE-d0XyWOszSetAItLpx0VrlxDkZeT4qTtxwXiu1Ad2xiAiPPtojFwBbzXlSTPScowuQCHv5-DvnpkxZU6adnM6YA00A7MAmtkTWusOk9p30YnTu_cYkAAaHvkhYj-RxtlSJ96_uOQfW-wrWD3ontjuy97pL08SNxnziXqx9KTudp148fYvb91u-vzeumqt9XmCGvfPSU8dFG4jBIYOelRzAC41VG4uZS37a9YG7OUy1c3sGr-pBzLdUdbA_0wG96IZM8pcBm7UF8R0zGtI6YPa0bX56hfeIcr_7E-Tu8VMIfvKhr8KoLe1v13z09eNX1k53XeexQEw_ur8PVeXHDn1zrxR1_evjRnwd3J5cXdypM2IFbEPPiJvxaurj5nkG3GLidIaYXXIEJNGuW8cbLi-rsgxd15uPGN6mzv4zv8Qvc335ZK516UAsCr_G2oyfF3-HEO-HBKevKvf6sfv7VH3rIg1PY_sEJJvtcnDzRLcEJfJau9Dc-qQdePMKHvtQy-IQVt_XU3dNIMDnfc_G7w3mmnuEp0CFi4oHN-SObPFRN54_637lG6n7MeFrndZo4hL7Jc1tpTL2bQi8pdMuVHy7I9ZpQrjnTSOw_R2eWHw=="
}

I receive this in info.txt :

{"response": {"status": {"version": "4.2", "code": 0, "message": "Success"}, "songs": []}}