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avcodec/pcm: use compile-time guards for PCM table init

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Change the PCM table init to use compile-time #if instead of a runtime
`if (CONFIG_...)`. This makes sure code for disabled encoders never gets
built, without depending on compiler dead-code elimination.

Signed-off-by: YiboFang <fangyibo@xiaomi.com>
Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
This commit is contained in:
YiboFang
2025-08-26 15:54:33 +08:00
committed by Zhao Zhili
parent f317b6c052
commit ae448e00af
2 changed files with 65 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files
libavcodec/pcm.c
+43 -10
View File
@@ -43,16 +43,27 @@ static av_cold int pcm_encode_init(AVCodecContext *avctx)
avctx->frame_size = 0;
#if !CONFIG_HARDCODED_TABLES
switch (avctx->codec->id) {
#define INIT_ONCE(id, name) \
case AV_CODEC_ID_PCM_ ## id: \
if (CONFIG_PCM_ ## id ## _ENCODER) { \
static AVOnce init_static_once = AV_ONCE_INIT; \
ff_thread_once(&init_static_once, pcm_ ## name ## _tableinit); \
} \
break
INIT_ONCE(ALAW, alaw);
INIT_ONCE(MULAW, ulaw);
INIT_ONCE(VIDC, vidc);
#if CONFIG_PCM_ALAW_ENCODER
case AV_CODEC_ID_PCM_ALAW: {
static AVOnce once_alaw = AV_ONCE_INIT;
ff_thread_once(&once_alaw, pcm_alaw_tableinit);
break;
}
#endif
#if CONFIG_PCM_MULAW_ENCODER
case AV_CODEC_ID_PCM_MULAW: {
static AVOnce once_mulaw = AV_ONCE_INIT;
ff_thread_once(&once_mulaw, pcm_ulaw_tableinit);
break;
}
#endif
#if CONFIG_PCM_VIDC_ENCODER
case AV_CODEC_ID_PCM_VIDC: {
static AVOnce once_vidc = AV_ONCE_INIT;
ff_thread_once(&once_vidc, pcm_vidc_tableinit);
break;
}
#endif
default:
break;
}
@@ -216,24 +227,30 @@ static int pcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
bytestream_put_buffer(&dst, src, n * sample_size);
}
break;
#if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_ALAW_ENCODER
case AV_CODEC_ID_PCM_ALAW:
for (; n > 0; n--) {
v = *samples++;
*dst++ = linear_to_alaw[(v + 32768) >> 2];
}
break;
#endif
#if CONFIG_PCM_MULAW_DECODER || CONFIG_PCM_MULAW_ENCODER
case AV_CODEC_ID_PCM_MULAW:
for (; n > 0; n--) {
v = *samples++;
*dst++ = linear_to_ulaw[(v + 32768) >> 2];
}
break;
#endif
#if CONFIG_PCM_VIDC_DECODER || CONFIG_PCM_VIDC_ENCODER
case AV_CODEC_ID_PCM_VIDC:
for (; n > 0; n--) {
v = *samples++;
*dst++ = linear_to_vidc[(v + 32768) >> 2];
}
break;
#endif
default:
return -1;
}
@@ -329,18 +346,24 @@ static av_cold av_unused int pcm_lut_decode_init(AVCodecContext *avctx)
switch (avctx->codec_id) {
default:
av_unreachable("pcm_lut_decode_init() only used with alaw, mulaw and vidc");
#if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_ALAW_ENCODER
case AV_CODEC_ID_PCM_ALAW:
for (int i = 0; i < 256; i++)
s->table[i] = alaw2linear(i);
break;
#endif
#if CONFIG_PCM_MULAW_DECODER || CONFIG_PCM_MULAW_ENCODER
case AV_CODEC_ID_PCM_MULAW:
for (int i = 0; i < 256; i++)
s->table[i] = ulaw2linear(i);
break;
#endif
#if CONFIG_PCM_VIDC_DECODER || CONFIG_PCM_VIDC_ENCODER
case AV_CODEC_ID_PCM_VIDC:
for (int i = 0; i < 256; i++)
s->table[i] = vidc2linear(i);
break;
#endif
}
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
@@ -547,6 +570,9 @@ static int pcm_decode_frame(AVCodecContext *avctx, AVFrame *frame,
bytestream_get_buffer(&src, samples, n * sample_size);
}
break;
#if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_ALAW_ENCODER || \
CONFIG_PCM_MULAW_DECODER || CONFIG_PCM_MULAW_ENCODER || \
CONFIG_PCM_VIDC_DECODER || CONFIG_PCM_VIDC_ENCODER
case AV_CODEC_ID_PCM_ALAW:
case AV_CODEC_ID_PCM_MULAW:
case AV_CODEC_ID_PCM_VIDC: {
@@ -557,6 +583,7 @@ static int pcm_decode_frame(AVCodecContext *avctx, AVFrame *frame,
*samples_16++ = lut[*src++];
break;
}
#endif
case AV_CODEC_ID_PCM_LXF:
{
int i;
@@ -657,7 +684,9 @@ const FFCodec ff_ ## name_ ## _decoder = { \
* to the table in pcm_decode_init() as well. */
// AV_CODEC_ID_* pcm_* name
// AV_SAMPLE_FMT_* long name DecodeContext decode init func
#if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_ALAW_ENCODER
PCM_CODEC_EXT(ALAW, S16, alaw, "PCM A-law / G.711 A-law", PCMLUTDecode, pcm_lut_decode_init);
#endif
PCM_DEC_EXT (F16LE, FLT, f16le, "PCM 16.8 floating point little-endian", PCMScaleDecode, pcm_scale_decode_init);
PCM_DEC_EXT (F24LE, FLT, f24le, "PCM 24.0 floating point little-endian", PCMScaleDecode, pcm_scale_decode_init);
PCM_CODEC (F32BE, FLT, f32be, "PCM 32-bit floating point big-endian");
@@ -665,7 +694,9 @@ PCM_CODEC (F32LE, FLT, f32le, "PCM 32-bit floating point little
PCM_CODEC (F64BE, DBL, f64be, "PCM 64-bit floating point big-endian");
PCM_CODEC (F64LE, DBL, f64le, "PCM 64-bit floating point little-endian");
PCM_DECODER (LXF, S32P,lxf, "PCM signed 20-bit little-endian planar");
#if CONFIG_PCM_MULAW_DECODER || CONFIG_PCM_MULAW_ENCODER
PCM_CODEC_EXT(MULAW, S16, mulaw, "PCM mu-law / G.711 mu-law", PCMLUTDecode, pcm_lut_decode_init);
#endif
PCM_CODEC (S8, U8, s8, "PCM signed 8-bit");
PCM_CODEC (S8_PLANAR, U8P, s8_planar, "PCM signed 8-bit planar");
PCM_CODEC (S16BE, S16, s16be, "PCM signed 16-bit big-endian");
@@ -688,5 +719,7 @@ PCM_CODEC (U32BE, S32, u32be, "PCM unsigned 32-bit big-endian")
PCM_CODEC (U32LE, S32, u32le, "PCM unsigned 32-bit little-endian");
PCM_CODEC (S64BE, S64, s64be, "PCM signed 64-bit big-endian");
PCM_CODEC (S64LE, S64, s64le, "PCM signed 64-bit little-endian");
#if CONFIG_PCM_VIDC_DECODER || CONFIG_PCM_VIDC_ENCODER
PCM_CODEC_EXT(VIDC, S16, vidc, "PCM Archimedes VIDC", PCMLUTDecode, pcm_lut_decode_init);
#endif
PCM_DECODER (SGA, U8, sga, "PCM SGA");
libavcodec/pcm_tablegen.h
+22
View File
@@ -42,6 +42,7 @@
#define VIDC_SEG_SHIFT (5)
#define VIDC_SEG_MASK (0xE0)
#if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_ALAW_ENCODER
/* alaw2linear() - Convert an A-law value to 16-bit linear PCM */
static av_cold int alaw2linear(unsigned char a_val)
{
@@ -57,7 +58,9 @@ static av_cold int alaw2linear(unsigned char a_val)
return (a_val & SIGN_BIT) ? t : -t;
}
#endif
#if CONFIG_PCM_MULAW_DECODER || CONFIG_PCM_MULAW_ENCODER
static av_cold int ulaw2linear(unsigned char u_val)
{
int t;
@@ -74,7 +77,9 @@ static av_cold int ulaw2linear(unsigned char u_val)
return (u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS);
}
#endif
#if CONFIG_PCM_VIDC_DECODER || CONFIG_PCM_VIDC_ENCODER
static av_cold int vidc2linear(unsigned char u_val)
{
int t;
@@ -88,6 +93,7 @@ static av_cold int vidc2linear(unsigned char u_val)
return (u_val & VIDC_SIGN_BIT) ? (BIAS - t) : (t - BIAS);
}
#endif
#if CONFIG_HARDCODED_TABLES
#define pcm_alaw_tableinit()
@@ -96,10 +102,19 @@ static av_cold int vidc2linear(unsigned char u_val)
#include "libavcodec/pcm_tables.h"
#else
/* 16384 entries per table */
#if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_ALAW_ENCODER
static uint8_t linear_to_alaw[16384];
#endif
#if CONFIG_PCM_MULAW_DECODER || CONFIG_PCM_MULAW_ENCODER
static uint8_t linear_to_ulaw[16384];
#endif
#if CONFIG_PCM_VIDC_DECODER || CONFIG_PCM_VIDC_ENCODER
static uint8_t linear_to_vidc[16384];
#endif
#if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_ALAW_ENCODER || \
CONFIG_PCM_MULAW_DECODER || CONFIG_PCM_MULAW_ENCODER || \
CONFIG_PCM_VIDC_DECODER || CONFIG_PCM_VIDC_ENCODER
static av_cold void build_xlaw_table(uint8_t *linear_to_xlaw,
int (*xlaw2linear)(unsigned char),
int mask)
@@ -123,21 +138,28 @@ static av_cold void build_xlaw_table(uint8_t *linear_to_xlaw,
}
linear_to_xlaw[0] = linear_to_xlaw[1];
}
#endif
#if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_ALAW_ENCODER
static void pcm_alaw_tableinit(void)
{
build_xlaw_table(linear_to_alaw, alaw2linear, 0xd5);
}
#endif
#if CONFIG_PCM_MULAW_DECODER || CONFIG_PCM_MULAW_ENCODER
static void pcm_ulaw_tableinit(void)
{
build_xlaw_table(linear_to_ulaw, ulaw2linear, 0xff);
}
#endif
#if CONFIG_PCM_VIDC_DECODER || CONFIG_PCM_VIDC_ENCODER
static void pcm_vidc_tableinit(void)
{
build_xlaw_table(linear_to_vidc, vidc2linear, 0xff);
}
#endif
#endif /* CONFIG_HARDCODED_TABLES */
#endif /* AVCODEC_PCM_TABLEGEN_H */