libavutil/samplefmt.c
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00001 /*
00002  * This file is part of Libav.
00003  *
00004  * Libav is free software; you can redistribute it and/or
00005  * modify it under the terms of the GNU Lesser General Public
00006  * License as published by the Free Software Foundation; either
00007  * version 2.1 of the License, or (at your option) any later version.
00008  *
00009  * Libav is distributed in the hope that it will be useful,
00010  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00011  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012  * Lesser General Public License for more details.
00013  *
00014  * You should have received a copy of the GNU Lesser General Public
00015  * License along with Libav; if not, write to the Free Software
00016  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00017  */
00018 
00019 #include "samplefmt.h"
00020 
00021 #include <stdio.h>
00022 #include <stdlib.h>
00023 #include <string.h>
00024 
00025 typedef struct SampleFmtInfo {
00026     const char *name;
00027     int bits;
00028     int planar;
00029 } SampleFmtInfo;
00030 
00032 static const SampleFmtInfo sample_fmt_info[AV_SAMPLE_FMT_NB] = {
00033     [AV_SAMPLE_FMT_U8]   = { .name =   "u8", .bits =  8, .planar = 0 },
00034     [AV_SAMPLE_FMT_S16]  = { .name =  "s16", .bits = 16, .planar = 0 },
00035     [AV_SAMPLE_FMT_S32]  = { .name =  "s32", .bits = 32, .planar = 0 },
00036     [AV_SAMPLE_FMT_FLT]  = { .name =  "flt", .bits = 32, .planar = 0 },
00037     [AV_SAMPLE_FMT_DBL]  = { .name =  "dbl", .bits = 64, .planar = 0 },
00038     [AV_SAMPLE_FMT_U8P]  = { .name =  "u8p", .bits =  8, .planar = 1 },
00039     [AV_SAMPLE_FMT_S16P] = { .name = "s16p", .bits = 16, .planar = 1 },
00040     [AV_SAMPLE_FMT_S32P] = { .name = "s32p", .bits = 32, .planar = 1 },
00041     [AV_SAMPLE_FMT_FLTP] = { .name = "fltp", .bits = 32, .planar = 1 },
00042     [AV_SAMPLE_FMT_DBLP] = { .name = "dblp", .bits = 64, .planar = 1 },
00043 };
00044 
00045 const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt)
00046 {
00047     if (sample_fmt < 0 || sample_fmt >= AV_SAMPLE_FMT_NB)
00048         return NULL;
00049     return sample_fmt_info[sample_fmt].name;
00050 }
00051 
00052 enum AVSampleFormat av_get_sample_fmt(const char *name)
00053 {
00054     int i;
00055 
00056     for (i = 0; i < AV_SAMPLE_FMT_NB; i++)
00057         if (!strcmp(sample_fmt_info[i].name, name))
00058             return i;
00059     return AV_SAMPLE_FMT_NONE;
00060 }
00061 
00062 char *av_get_sample_fmt_string (char *buf, int buf_size, enum AVSampleFormat sample_fmt)
00063 {
00064     /* print header */
00065     if (sample_fmt < 0)
00066         snprintf(buf, buf_size, "name  " " depth");
00067     else if (sample_fmt < AV_SAMPLE_FMT_NB) {
00068         SampleFmtInfo info = sample_fmt_info[sample_fmt];
00069         snprintf (buf, buf_size, "%-6s" "   %2d ", info.name, info.bits);
00070     }
00071 
00072     return buf;
00073 }
00074 
00075 int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt)
00076 {
00077      return sample_fmt < 0 || sample_fmt >= AV_SAMPLE_FMT_NB ?
00078         0 : sample_fmt_info[sample_fmt].bits >> 3;
00079 }
00080 
00081 #if FF_API_GET_BITS_PER_SAMPLE_FMT
00082 int av_get_bits_per_sample_fmt(enum AVSampleFormat sample_fmt)
00083 {
00084     return sample_fmt < 0 || sample_fmt >= AV_SAMPLE_FMT_NB ?
00085         0 : sample_fmt_info[sample_fmt].bits;
00086 }
00087 #endif
00088 
00089 int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt)
00090 {
00091      if (sample_fmt < 0 || sample_fmt >= AV_SAMPLE_FMT_NB)
00092          return 0;
00093      return sample_fmt_info[sample_fmt].planar;
00094 }
00095 
00096 int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples,
00097                                enum AVSampleFormat sample_fmt, int align)
00098 {
00099     int line_size;
00100     int sample_size = av_get_bytes_per_sample(sample_fmt);
00101     int planar      = av_sample_fmt_is_planar(sample_fmt);
00102 
00103     /* validate parameter ranges */
00104     if (!sample_size || nb_samples <= 0 || nb_channels <= 0)
00105         return AVERROR(EINVAL);
00106 
00107     /* auto-select alignment if not specified */
00108     if (!align)
00109         align = 32;
00110 
00111     /* check for integer overflow */
00112     if (nb_channels > INT_MAX / align ||
00113         (int64_t)nb_channels * nb_samples > (INT_MAX - (align * nb_channels)) / sample_size)
00114         return AVERROR(EINVAL);
00115 
00116     line_size = planar ? FFALIGN(nb_samples * sample_size,               align) :
00117                          FFALIGN(nb_samples * sample_size * nb_channels, align);
00118     if (linesize)
00119         *linesize = line_size;
00120 
00121     return planar ? line_size * nb_channels : line_size;
00122 }
00123 
00124 int av_samples_fill_arrays(uint8_t **audio_data, int *linesize,
00125                            uint8_t *buf, int nb_channels, int nb_samples,
00126                            enum AVSampleFormat sample_fmt, int align)
00127 {
00128     int ch, planar, buf_size;
00129 
00130     planar   = av_sample_fmt_is_planar(sample_fmt);
00131     buf_size = av_samples_get_buffer_size(linesize, nb_channels, nb_samples,
00132                                           sample_fmt, align);
00133     if (buf_size < 0)
00134         return buf_size;
00135 
00136     audio_data[0] = buf;
00137     for (ch = 1; planar && ch < nb_channels; ch++)
00138         audio_data[ch] = audio_data[ch-1] + *linesize;
00139 
00140     return 0;
00141 }
00142 
00143 int av_samples_alloc(uint8_t **audio_data, int *linesize, int nb_channels,
00144                      int nb_samples, enum AVSampleFormat sample_fmt, int align)
00145 {
00146     uint8_t *buf;
00147     int size = av_samples_get_buffer_size(NULL, nb_channels, nb_samples,
00148                                           sample_fmt, align);
00149     if (size < 0)
00150         return size;
00151 
00152     buf = av_mallocz(size);
00153     if (!buf)
00154         return AVERROR(ENOMEM);
00155 
00156     size = av_samples_fill_arrays(audio_data, linesize, buf, nb_channels,
00157                                   nb_samples, sample_fmt, align);
00158     if (size < 0) {
00159         av_free(buf);
00160         return size;
00161     }
00162     return 0;
00163 }