diff options
Diffstat (limited to 'main')
| -rw-r--r-- | main/http_api.c | 45 |
1 files changed, 44 insertions, 1 deletions
diff --git a/main/http_api.c b/main/http_api.c index 4e03868..c490a85 100644 --- a/main/http_api.c +++ b/main/http_api.c @@ -283,6 +283,10 @@ static esp_err_t state_post_handler(httpd_req_t *req) viewport_run_state_t target; if (strcmp(j->valuestring, "wake") == 0) { target = VIEWPORT_STATE_AWAKE; + // Reset the pipelined-POST sequence comparator so the next + // stream's first frame isn't rejected as stale just because + // the previous stream's counter happened to be higher. + s_last_painted_seq = 0; } else if (strcmp(j->valuestring, "sleep") == 0) { target = VIEWPORT_STATE_ASLEEP; } else { @@ -315,7 +319,18 @@ static esp_err_t respond_status(httpd_req_t *req, const char *status, const char // Tracks when the previous /frame response finished so we can log the // idle gap until the next request enters. Large idle = Scrypted/network // upstream is the bottleneck; small idle = we're saturating the link. -static int64_t s_last_post_us; +static int64_t s_last_post_us; +// Highest X-Frame-Seq value we've actually painted. With two /frame +// POSTs pipelined over separate sockets the firmware's decoder mutex +// is the serialisation point, but FreeRTOS semaphore acquisition is +// not FIFO — under jitter task B can grab the lock for frame N+1 +// before task A grabs it for frame N. Without a sequence check, the +// later-arriving older frame would paint over the newer one and the +// panel would briefly travel backwards in time. Frames with seq <= +// s_last_painted_seq are acknowledged 200 OK but not painted. Reset +// to 0 on every device wake — Scrypted's counter starts fresh per +// stream so we don't drag a stale comparison forward. +static uint32_t s_last_painted_seq; static esp_err_t frame_post_handler(httpd_req_t *req) { @@ -345,6 +360,16 @@ static esp_err_t frame_post_handler(httpd_req_t *req) int64_t t_entry = esp_timer_get_time(); + // Read the optional X-Frame-Seq header used to keep pipelined + // POSTs in monotonic paint order. Missing or zero header = no + // ordering enforcement (treat every frame as newer than the + // previous one, same behaviour we had before pipelining). + uint32_t seq = 0; + char seq_str[16] = {0}; + if (httpd_req_get_hdr_value_str(req, "X-Frame-Seq", seq_str, sizeof(seq_str)) == ESP_OK) { + seq = (uint32_t)strtoul(seq_str, NULL, 10); + } + // Single in-flight frame. Concurrent posts get 503 (spec). if (!jpeg_decoder_try_lock(0)) { return respond_status(req, "503 Service Unavailable", "frame in flight"); @@ -370,6 +395,22 @@ static esp_err_t frame_post_handler(httpd_req_t *req) int64_t t_recv = esp_timer_get_time(); + // Pipelined-POST stale-frame check. With the X-Frame-Seq header + // set, drop anything we've already advanced past — we hold the + // decoder lock, so re-checking here is race-free. Without the + // header (seq==0) every frame paints, preserving pre-pipelining + // behaviour. + if (seq != 0 && seq <= s_last_painted_seq) { + jpeg_decoder_unlock(); + // 200 OK with an empty body keeps the keep-alive socket + // healthy and lets Scrypted's per-fetch wall-clock log + // stay accurate; we just won't count this toward + // frames_received. + httpd_resp_set_status(req, "200 OK"); + httpd_resp_set_hdr(req, "X-Frame-Drop", "stale-seq"); + return httpd_resp_send(req, NULL, 0); + } + // Decode straight into the panel's back framebuffer — no scratch // buffer, no later memcpy. The flip below is a cache writeback + // index swap inside the IDF DPI driver. @@ -416,6 +457,8 @@ static esp_err_t frame_post_handler(httpd_req_t *req) uint64_t fr = st->frames_received; viewport_state_unlock(); + if (seq != 0) s_last_painted_seq = seq; + jpeg_decoder_unlock(); // Track the bookkeeping tail too so we can see if anything between |