On Sat, 19 Jul 2014 19:21:47 -0400
siret...@gmail.com wrote:
> From: John Peterson <john.peters...@hotmail.com>
>
> Useful to simulate low performance input.
> The minimum resolution is 1 Kib/s.
>
> The input stream packet size setting can be used to test the performance
> with different packet sizes at the maximum or simulated maximum input
> rate.
> ---
> libavformat/avio.h | 15 ++++++++++++
> libavformat/aviobuf.c | 63
> +++++++++++++++++++++++++++++++++++++++++++++++++++
> libavformat/utils.c | 5 +++-
> 3 files changed, 82 insertions(+), 1 deletion(-)
>
> diff --git a/libavformat/avio.h b/libavformat/avio.h
> index 3360e82..b16fd00 100644
> --- a/libavformat/avio.h
> +++ b/libavformat/avio.h
> @@ -54,6 +54,19 @@ typedef struct AVIOInterruptCB {
> } AVIOInterruptCB;
>
> /**
> + * Input stream throttle queue.
> + */
> +typedef struct traffic {
> + int64_t time;
> + int traf;
> +} traffic;
> +typedef struct traffic_queue {
> + int size;
> + int len;
> + traffic *data;
> +} traffic_queue;
> +
> +/**
> * Bytestream IO Context.
> * New fields can be added to the end with minor version bumps.
> * Removal, reordering and changes to existing fields require a major
> @@ -96,6 +109,8 @@ typedef struct AVIOContext {
> int eof_reached; /**< true if eof reached */
> int write_flag; /**< true if open for writing */
> int max_packet_size;
> + int throttle; /**< command line argument throttle */
> + traffic_queue t_queue; /**< traffic queue for throttle */
> unsigned long checksum;
> unsigned char *checksum_ptr;
> unsigned long (*update_checksum)(unsigned long checksum, const uint8_t
> *buf, unsigned int size);
> diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
> index cc79146..f957625 100644
> --- a/libavformat/aviobuf.c
> +++ b/libavformat/aviobuf.c
> @@ -30,8 +30,10 @@
> #include "internal.h"
> #include "url.h"
> #include <stdarg.h>
> +#include <unistd.h>
>
> #define IO_BUFFER_SIZE 32768
> +#define INPUT_HISTORY_SIZE 10 // s
>
> /**
> * Do seeks within this distance ahead of the current buffer by skipping
> @@ -51,7 +53,11 @@ static const AVClass *ffio_url_child_class_next(const
> AVClass *prev)
> return prev ? NULL : &ffurl_context_class;
> }
>
> +#define OFFSET(x) offsetof(AVIOContext, x)
> +#define D AV_OPT_FLAG_DECODING_PARAM
> static const AVOption ffio_url_options[] = {
> + { "in_packet_size", "set max input packet size",
> OFFSET(max_packet_size), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, D },
> + { "throttle", "set max input rate in Kib/s", OFFSET(throttle),
> AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, D },
> { NULL },
> };
>
> @@ -359,6 +365,57 @@ void avio_wb24(AVIOContext *s, unsigned int val)
>
> /* Input stream */
>
> +/* traffic history for input throttle */
> +static void t_queue_push(traffic_queue *queue, int64_t time, int traf)
> +{
> + traffic* data;
> + queue->len++;
> + data = av_realloc(queue->data, sizeof(traffic)*queue->len);
> + if (!data)
> + return;
> + queue->data = data;
> + queue->data[queue->len-1].time = time;
> + queue->data[queue->len-1].traf = traf;
> +}
> +
> +static void t_queue_pop(traffic_queue *queue)
> +{
> + int i;
> + for (i = 0; i < queue->len; i++) {
> + if (queue->data[i].time < av_gettime()-INPUT_HISTORY_SIZE*1000000) {
> + memmove(queue->data + i, queue->data + i + 1,
> sizeof(traffic)*(queue->len - i - 1));
> + queue->len--;
> + }
> + }
> +}
> +
> +/* input throttle */
> +static int64_t avio_throttle_rate(traffic_queue *queue, int64_t time)
> +{
> + int64_t sum = 0;
> + int i;
> + for (i = 0; i < queue->len; i++) {
> + if (queue->data[i].time > av_gettime()-time)
> + sum += queue->data[i].traf;
> + }
> + return (double)sum/((double)time/1000000.0); // B/s
> +}
> +
> +static int avio_throttle(AVIOContext *s)
> +{
> + if (!s->throttle) return 0;
> + t_queue_pop(&s->t_queue);
> + // measure speed at multiple intervals to create an even transfer rate
> + if (avio_throttle_rate(&s->t_queue, 0.001*1000000) > s->throttle*0x80
> + || avio_throttle_rate(&s->t_queue, 0.01*1000000) > s->throttle*0x80
> + || avio_throttle_rate(&s->t_queue, 0.1*1000000) > s->throttle*0x80
> + || avio_throttle_rate(&s->t_queue, 1*1000000) > s->throttle*0x80
> + || avio_throttle_rate(&s->t_queue, 10*1000000) > s->throttle*0x80
> + )
> + return 1;
> + return 0;
> +}
> +
> static void fill_buffer(AVIOContext *s)
> {
> uint8_t *dst = !s->max_packet_size &&
> @@ -405,6 +462,12 @@ static void fill_buffer(AVIOContext *s)
> s->pos += len;
> s->buf_ptr = dst;
> s->buf_end = dst + len;
> +
> + // throttle
> + t_queue_push(&s->t_queue, av_gettime(), len);
> + while (s->throttle && avio_throttle(s)) {
> + usleep(0.1*1000000);
> + }
> }
> }
>
> diff --git a/libavformat/utils.c b/libavformat/utils.c
> index 7a054af..2211b9c 100644
> --- a/libavformat/utils.c
> +++ b/libavformat/utils.c
> @@ -427,8 +427,11 @@ int avformat_open_input(AVFormatContext **ps, const char
> *filename,
> }
>
> /* e.g. AVFMT_NOFILE formats will not have a AVIOContext */
> - if (s->pb)
> + if (s->pb) {
> ff_id3v2_read(s, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta);
> + if ((ret = av_opt_set_dict(s->pb, &tmp)) < 0)
> + goto fail;
> + }
>
> if (s->iformat->read_header)
> if ((ret = s->iformat->read_header(s)) < 0)
I'd say no. Useful for debugging sometimes (or is there a real
usecase???), but does it really have to be in the main repo? Also, this
should be implemented as nested protocol, not somehow hacking it into
aviobuf.c.
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