FreeCalypso > hg > gsm-codec-lib
comparison doc/AMR-library-tests @ 481:cc0c244bd233
doc/AMR-library-tests: new article
| author | Mychaela Falconia <falcon@freecalypso.org> |
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| date | Mon, 20 May 2024 01:02:37 +0000 |
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| 480:332397bc80aa | 481:cc0c244bd233 |
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| 1 The present suite includes a pair of command line programs that exercise | |
| 2 libtwamr encoder and decoder in 3GPP test sequence format, allowing this library | |
| 3 to be tested against the official test sequences of 3GPP TS 26.074. | |
| 4 | |
| 5 twamr-tseq-enc | |
| 6 ============== | |
| 7 | |
| 8 This program reads a *.inp file from the collection of TS 26.074, encodes it | |
| 9 per selected AMR mode using libtwamr functions, and emits the encoder output in | |
| 10 3GPP-defined .cod format. The command line structure of twamr-tseq-enc is as | |
| 11 follows: | |
| 12 | |
| 13 twamr-tseq-enc [-d] [-2] input.inp mode output.cod | |
| 14 | |
| 15 The middle argument specifies the codec mode to be used; there is no default. | |
| 16 Ordinarily the mode argument is one of these 8 keywords: | |
| 17 | |
| 18 MR475 | |
| 19 MR515 | |
| 20 MR59 | |
| 21 MR67 | |
| 22 MR74 | |
| 23 MR795 | |
| 24 MR102 | |
| 25 MR122 | |
| 26 | |
| 27 However, this mode argument can also take the form of "file:$modefile", where | |
| 28 $modefile is an ASCII text file giving one of the above mode keywords per line. | |
| 29 This form is needed when testing the encoding of t21.inp per t21.mod control | |
| 30 file. | |
| 31 | |
| 32 twamr-tseq-enc flag options: -d enables DTX, -2 switches the VAD algorithm from | |
| 33 VAD1 default to VAD2 alternative. The two options can be combined as -d2. | |
| 34 | |
| 35 twamr-tseq-dec | |
| 36 ============== | |
| 37 | |
| 38 This program reads a *.cod file in 3GPP AMR test sequence format, decodes it | |
| 39 using libtwamr functions, and emits the decoder output in a raw PCM *.out file. | |
| 40 The command line structure of twamr-tseq-dec is as follows: | |
| 41 | |
| 42 twamr-tseq-dec [-r] input.cod output.out | |
| 43 | |
| 44 By default the first word of each *.cod frame is expected to be a Tx frame type | |
| 45 as in enum TXFrameType; with -r option this first word is expected to be an Rx | |
| 46 frame type as in enum RXFrameType instead. This option directly corresponds to | |
| 47 -rxframetype in the reference decoder program from 3GPP. | |
| 48 | |
| 49 Byte order considerations | |
| 50 ========================= | |
| 51 | |
| 52 Both twamr-tseq-enc and twamr-tseq-dec read and write their input and output | |
| 53 files (16-bit linear PCM on one end and 3GPP *.cod test sequence format on the | |
| 54 other end) in the local machine's native byte order. 3GPP shipped their | |
| 55 TS 26.074 collection of AMR test sequences in little-endian byte order; given | |
| 56 that most GSM software developers are now largely forced by economic pressures | |
| 57 to work on x86 or ARM architecture machines rather than more noble SPARC or | |
| 58 PowerPC systems, the local byte order of the developer's machine will typically | |
| 59 be LE, matching TS 26.074 files as published. |