static int xbm_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { AVFrame *p = data; const uint8_t *end, *ptr = avpkt->data; uint8_t *dst; int ret, linesize, i, j; end = avpkt->data + avpkt->size; while (!avctx->width || !avctx->height) { char name[256]; int number, len; ptr += strcspn(ptr, "#"); if (sscanf(ptr, "#define %256s %u", name, &number) != 2) { av_log(avctx, AV_LOG_ERROR, "Unexpected preprocessor directive\n"); return AVERROR_INVALIDDATA; } len = strlen(name); if ((len > 6) && !avctx->height && !memcmp(name + len - 7, "_height", 7)) { avctx->height = number; } else if ((len > 5) && !avctx->width && !memcmp(name + len - 6, "_width", 6)) { avctx->width = number; } else { av_log(avctx, AV_LOG_ERROR, "Unknown define '%s'\n", name); return AVERROR_INVALIDDATA; } ptr += strcspn(ptr, "\n\r") + 1; } if ((ret = ff_get_buffer(avctx, p, 0)) < 0) return ret; // goto start of image data ptr += strcspn(ptr, "{") + 1; linesize = (avctx->width + 7) / 8; for (i = 0; i < avctx->height; i++) { dst = p->data[0] + i * p->linesize[0]; for (j = 0; j < linesize; j++) { uint8_t val; ptr += strcspn(ptr, "x") + 1; if (ptr < end && av_isxdigit(*ptr)) { val = convert(*ptr); ptr++; if (av_isxdigit(*ptr)) val = (val << 4) + convert(*ptr); *dst++ = ff_reverse[val]; } else { av_log(avctx, AV_LOG_ERROR, "Unexpected data at '%.8s'\n", ptr); return AVERROR_INVALIDDATA; } } } p->key_frame = 1; p->pict_type = AV_PICTURE_TYPE_I; *got_frame = 1; return avpkt->size; }