FreeCalypso > hg > gsm-codec-lib
view amrconv/amr2efr.c @ 477:4c9222d95647
libtwamr encoder: always emit frame->mode = mode;
In the original implementation of amr_encode_frame(), the 'mode' member
of the output struct was set to 0xFF if the output frame type is TX_NO_DATA.
This design was made to mimic the mode field (16-bit word) being set to
0xFFFF (or -1) in 3GPP test sequence format - but nothing actually depends
on this struct member being set in any way, and amr_frame_to_tseq()
generates the needed 0xFFFF on its own, based on frame->type being equal
to TX_NO_DATA.
It is simpler and more efficient to always set frame->mode to the actual
encoding mode in amr_encode_frame(), and this new behavior has already
been documented in doc/AMR-library-API description in anticipation of
the present change.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Sat, 18 May 2024 22:30:42 +0000 |
parents | b092a510141e |
children |
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/* * Our gsm-amr2efr utility reads in a speech recording in .amr format * (the mode must be MR122 for every frame, no DTX) and converts it into * our ad hoc .gsmx format for EFR. The conversion is a bit reshuffling * only, no transcoding takes place. */ #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <strings.h> extern const uint8_t amr_122_bit_order[244]; static const char amr_file_hdr[] = "#!AMR\n"; main(argc, argv) char **argv; { char *infname, *outfname; FILE *inf, *outf; int wrong_flag, hdrb; uint8_t frm_in[31], frm_out[31]; unsigned bit_a, bit_n; if (argc == 3 && argv[1][0] != '-') { wrong_flag = 0; infname = argv[1]; outfname = argv[2]; } else if (argc == 4 && !strcmp(argv[1], "-w")) { wrong_flag = 1; infname = argv[2]; outfname = argv[3]; } else { fprintf(stderr, "usage: %s [-w] input.amr output.gsmx\n", argv[0]); exit(1); } inf = fopen(infname, "r"); if (!inf) { perror(infname); exit(1); } if (fread(frm_in, 1, 6, inf) != 6 || bcmp(frm_in, amr_file_hdr, 6)) { fprintf(stderr, "error: %s is not in AMR format\n", infname); exit(1); } outf = fopen(outfname, "w"); if (!outf) { perror(outfname); exit(1); } for (;;) { hdrb = getc(inf); if (hdrb < 0) break; if ((hdrb & 0x78) != 0x38) { fprintf(stderr, "error: unexpected content in %s\n", infname); exit(1); } if (fread(frm_in, 1, 31, inf) != 31) { fprintf(stderr, "error: short read from %s\n", infname); exit(1); } frm_out[0] = 0xC0; for (bit_a = 0; bit_a < 244; bit_a++) { if (wrong_flag) bit_n = bit_a; else bit_n = amr_122_bit_order[bit_a]; msb_set_bit(frm_out, 4 + bit_n, msb_get_bit(frm_in, bit_a)); } fwrite(frm_out, 1, 31, outf); } fclose(outf); exit(0); }