[FFmpeg-devel] [PATCH 7/9] fftools/ffmpeg_filter: Avoid allocations when configuring output filters
Andreas Rheinhardt
andreas.rheinhardt at outlook.com
Tue Apr 6 08:40:14 EEST 2021
Use an AVBPrint to handle the (typically short) strings involved here.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
fftools/ffmpeg_filter.c | 99 +++++++++++++++++------------------------
1 file changed, 41 insertions(+), 58 deletions(-)
diff --git a/fftools/ffmpeg_filter.c b/fftools/ffmpeg_filter.c
index 5c44b75eff..61ca793058 100644
--- a/fftools/ffmpeg_filter.c
+++ b/fftools/ffmpeg_filter.c
@@ -127,45 +127,39 @@ static char *choose_pix_fmts(OutputFilter *ofilter)
return NULL;
}
-/* Define a function for building a string containing a list of
- * allowed formats. */
-#define DEF_CHOOSE_FORMAT(suffix, type, var, supported_list, none, get_name) \
-static char *choose_ ## suffix (OutputFilter *ofilter) \
+/* Define a function for appending a list of allowed formats
+ * to an AVBPrint. If nonempty, the list will have a header. */
+#define DEF_CHOOSE_FORMAT(name, type, var, supported_list, none, printf_format, get_name) \
+static void choose_ ## name (OutputFilter *ofilter, AVBPrint *bprint) \
{ \
+ if (ofilter->var == none && !ofilter->supported_list) \
+ return; \
+ av_bprintf(bprint, #name "="); \
if (ofilter->var != none) { \
- get_name(ofilter->var); \
- return av_strdup(name); \
- } else if (ofilter->supported_list) { \
+ av_bprintf(bprint, printf_format, get_name(ofilter->var)); \
+ } else { \
const type *p; \
- AVIOContext *s = NULL; \
- uint8_t *ret; \
- int len; \
- \
- if (avio_open_dyn_buf(&s) < 0) \
- exit_program(1); \
\
for (p = ofilter->supported_list; *p != none; p++) { \
- get_name(*p); \
- avio_printf(s, "%s|", name); \
+ av_bprintf(bprint, printf_format "|", get_name(*p)); \
} \
- len = avio_close_dyn_buf(s, &ret); \
- ret[len - 1] = 0; \
- return ret; \
- } else \
- return NULL; \
+ if (bprint->len > 0) \
+ bprint->str[--bprint->len] = '\0'; \
+ } \
+ av_bprint_chars(bprint, ':', 1); \
}
//DEF_CHOOSE_FORMAT(pix_fmts, enum AVPixelFormat, format, formats, AV_PIX_FMT_NONE,
// GET_PIX_FMT_NAME)
DEF_CHOOSE_FORMAT(sample_fmts, enum AVSampleFormat, format, formats,
- AV_SAMPLE_FMT_NONE, GET_SAMPLE_FMT_NAME)
+ AV_SAMPLE_FMT_NONE, "%s", av_get_sample_fmt_name)
DEF_CHOOSE_FORMAT(sample_rates, int, sample_rate, sample_rates, 0,
- GET_SAMPLE_RATE_NAME)
+ "%d", )
DEF_CHOOSE_FORMAT(channel_layouts, uint64_t, channel_layout, channel_layouts, 0,
- GET_CH_LAYOUT_NAME)
+ "0x%"PRIx64, )
int init_simple_filtergraph(InputStream *ist, OutputStream *ost)
{
@@ -525,7 +519,7 @@ static int configure_output_audio_filter(FilterGraph *fg, OutputFilter *ofilter,
AVCodecContext *codec = ost->enc_ctx;
AVFilterContext *last_filter = out->filter_ctx;
int pad_idx = out->pad_idx;
- char *sample_fmts, *sample_rates, *channel_layouts;
+ AVBPrint args;
char name[255];
int ret;
@@ -548,65 +542,52 @@ static int configure_output_audio_filter(FilterGraph *fg, OutputFilter *ofilter,
avfilter_get_by_name(filter_name), \
filter_name, arg, NULL, fg->graph); \
if (ret < 0) \
- return ret; \
+ goto fail; \
\
ret = avfilter_link(last_filter, pad_idx, filt_ctx, 0); \
if (ret < 0) \
- return ret; \
+ goto fail; \
\
last_filter = filt_ctx; \
pad_idx = 0; \
} while (0)
+ av_bprint_init(&args, 0, AV_BPRINT_SIZE_UNLIMITED);
if (ost->audio_channels_mapped) {
int i;
- AVBPrint pan_buf;
- av_bprint_init(&pan_buf, 256, 8192);
- av_bprintf(&pan_buf, "0x%"PRIx64,
+ av_bprintf(&args, "0x%"PRIx64,
av_get_default_channel_layout(ost->audio_channels_mapped));
for (i = 0; i < ost->audio_channels_mapped; i++)
if (ost->audio_channels_map[i] != -1)
- av_bprintf(&pan_buf, "|c%d=c%d", i, ost->audio_channels_map[i]);
+ av_bprintf(&args, "|c%d=c%d", i, ost->audio_channels_map[i]);
- AUTO_INSERT_FILTER("-map_channel", "pan", pan_buf.str);
- av_bprint_finalize(&pan_buf, NULL);
+ AUTO_INSERT_FILTER("-map_channel", "pan", args.str);
+ av_bprint_clear(&args);
}
if (codec->channels && !codec->channel_layout)
codec->channel_layout = av_get_default_channel_layout(codec->channels);
- sample_fmts = choose_sample_fmts(ofilter);
- sample_rates = choose_sample_rates(ofilter);
- channel_layouts = choose_channel_layouts(ofilter);
- if (sample_fmts || sample_rates || channel_layouts) {
+ choose_sample_fmts(ofilter, &args);
+ choose_sample_rates(ofilter, &args);
+ choose_channel_layouts(ofilter, &args);
+ if (!av_bprint_is_complete(&args)) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+ if (args.len) {
AVFilterContext *format;
- char args[256];
- args[0] = 0;
-
- if (sample_fmts)
- av_strlcatf(args, sizeof(args), "sample_fmts=%s:",
- sample_fmts);
- if (sample_rates)
- av_strlcatf(args, sizeof(args), "sample_rates=%s:",
- sample_rates);
- if (channel_layouts)
- av_strlcatf(args, sizeof(args), "channel_layouts=%s:",
- channel_layouts);
-
- av_freep(&sample_fmts);
- av_freep(&sample_rates);
- av_freep(&channel_layouts);
snprintf(name, sizeof(name), "format_out_%d_%d",
ost->file_index, ost->index);
ret = avfilter_graph_create_filter(&format,
avfilter_get_by_name("aformat"),
- name, args, NULL, fg->graph);
+ name, args.str, NULL, fg->graph);
if (ret < 0)
- return ret;
+ goto fail;
ret = avfilter_link(last_filter, pad_idx, format, 0);
if (ret < 0)
- return ret;
+ goto fail;
last_filter = format;
pad_idx = 0;
@@ -631,12 +612,14 @@ static int configure_output_audio_filter(FilterGraph *fg, OutputFilter *ofilter,
ret = insert_trim(of->start_time, of->recording_time,
&last_filter, &pad_idx, name);
if (ret < 0)
- return ret;
+ goto fail;
if ((ret = avfilter_link(last_filter, pad_idx, ofilter->filter, 0)) < 0)
- return ret;
+ goto fail;
+fail:
+ av_bprint_finalize(&args, NULL);
- return 0;
+ return ret;
}
static int configure_output_filter(FilterGraph *fg, OutputFilter *ofilter,
--
2.27.0
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